Glass Box Diaries

Adding New Fish for My 25L Planted Aquarium! (Nano Tank)

It was finally time to choose fish for my new 25-litre, or 6.6 US-gallon, planted tank. The tank finished cycling a week ago, so I tested the water before heading to Gateshead Guppies.

For a planted aquarium this size, Endlers are a great choice. I looked at some Scarlet Endlers and was very close to bringing home Japan Blue Endlers, but I think I will save those for another tank.

Then I spotted these Tiger Endlers and instantly knew they were the ones. I picked up two pairs, but because Endlers are such prolific livebearers, I made sure I had a plan for any fry before buying them. The shop is happy to take babies back, and I also have a friend with a dedicated livebearer breeding room who can take some if needed.

Once I got home, I moved the fish into a tub, used a comb to remove the duckweed from the shop water, and got them into their new aquarium quickly. I did not drip acclimate them because they had only been in the bags for a short time, and I wanted to avoid prolonging that. The best acclimation method depends on how different the shop and aquarium water are.

The tank is now fully cycled, so ammonia and nitrite are under control. The Seiryu stone is also helping raise the pH, GH, and KH into a range that better suits these fish. These are Endler guppies rather than pure Endler’s livebearers, meaning they are hybrids between Endlers and guppies.

I was not sure when they had last been fed, so I offered a small amount of micro granules. They settled in straight away, started exploring the plants, and quickly discovered the tiny copepod colony that appeared during the cycle. Hopefully, a few copepods will survive among the leaf litter and help turn this little tank into an even more natural ecosystem.

Two years without a heater, and this is still one of my favourite tanks. Full Video Update - https://www.youtube.com/watch?v=RkUkWvPXjZM

This 45-litre planted aquarium runs at room temperature, dropping to around 18°C in winter and reaching about 25°C during summer.

It is home to Golden White Cloud Mountain Minnows, yellow Neocaridina shrimp, ramshorn snails, Anubias, Bucephalandra, Helanthium tenellum, and a few plants that have proven far tougher than I expected.

I Lost Half My Medaka Fry in A Heatwave!

I lost around half of my baby Medaka fry during this summer’s heatwaves, but moving the rest into this tank seems to have saved them.

I hatched these Medaka rice fish earlier this summer from rare eggs I got from Medaka Rice Fish UK on Instagram, and the initial hatch went really well. Medaka are temperate fish that generally prefer cooler water, though, and the tiny fry really struggled once the heatwaves arrived.

After losing around half during the first few hot spells, I moved the remaining fry into this established, filterless shrimp tank. There are no fish in here that could eat them, no filter intake or moving parts that could present a risk, and plenty of plants for cover and grazing.

Most importantly, this is a much easier tank for me to keep cool. I can run my tower fans directly across the surface, and I add an air stone when temperatures rise to keep the water moving and oxygen levels up. During a heatwave, especially with small fry, keeping the water well oxygenated can be just as important as trying to lower the temperature itself.

The third and fourth heatwaves have now passed, and thankfully I have not noticed any more losses. The plant cover means I cannot get an exact count, but I have consistently been able to spot ten fry at the same time, which is encouraging.

We are expecting another heatwave soon, but I feel much more confident in this setup now. The fans, extra aeration, established plants, and lack of predators have made it a far safer place for them to grow out.

Best of all, the fry seem to be doing really well. In the five weeks they have lived in this tank, they have more than doubled in size.

Adding Cherry Shrimp to a New Aquarium Safely!

My Cherry Shrimp Care Guide - https://glassboxdiaries.com/care_guide/neocaridina-shrimp-care/ My Amano Shrimp Care Guide - https://glassboxdiaries.com/care_guide/amano-shrimp/

Shrimp acclimation is not one-size-fits-all.

There are several ways to acclimate cherry shrimp after buying them, and the best method depends on how different the breeder’s water is from your aquarium water. I have shared videos of myself unboxing new shrimp and had some people say I am acclimating them for far too long, while others on the exact same video say I am not doing it for long enough.

The question is: how do they know the difference between my water and the breeder’s?

A good shrimp breeder should be happy to tell you the water parameters their shrimp are kept and bred in. I regularly buy from Best Aquarium Shrimp UK, and my own soft tap water is very different from theirs. Because of that, I gradually acclimate new shrimp over a couple of hours, giving them time to adjust and reducing the risk of osmotic shock.

But a friend of mine lives in the same city and receives harder tap water from a reservoir farther north. His water parameters are almost identical to the breeder’s. As his tanks are also unheated, the shrimp have already reached a very similar temperature during shipping. He can pour them through a net to remove the shipping water, then add them straight into the aquarium without issues.

Both approaches can work perfectly well in the right circumstances.

The problem is blindly copying somebody else’s method without knowing whether your aquarium water is actually similar to theirs. That is why one person can add shrimp straight in with no losses, while somebody else does exactly the same thing and loses every shrimp they bought.

If you keep Neocaridina, cherry shrimp, Bloody Mary shrimp, or any other freshwater shrimp, I would always recommend a suitable liquid test kit that includes GH, plus a TDS meter. Compare your aquarium water with the breeder’s parameters, consider the temperature difference, and choose an acclimation method based on the actual change your shrimp need to make.

Your Aquarium Light Might Be Lying to You!

Two aquarium lights can cost the same, look nearly identical, but give your plants completely different amounts of usable light.

That is why choosing a planted tank light by its price, wattage, or the claims on the box can be an expensive mistake. Wattage only tells you a light’s energy use. It does not tell you how much useful light reaches your plants or which wavelengths it produces.

Once a year, I rent an ITC PARwise meter from parmeterhire.co.uk and test every aquarium light in my fish room. Their PAR-meter hire starts at £25 for five days, and it arrives with everything needed to return it, including the return bag and address labels.

PAR means photosynthetically active radiation: the light plants can use for photosynthesis. A PAR reading gives you a much more useful starting point than marketing claims, particularly for demanding, carpeting, or red plants.

The PARwise also produces a spectral power distribution graph, showing the wavelengths a light is making. That matters because a light can achieve a respectable PAR figure by peaking heavily in blue, while producing very little red around chlorophyll’s second major absorption peak.

Its wand sensor also lets you map your aquarium. You can compare the PAR at the surface, mid-water, and substrate, then check whether tall stems, floating plants, hardscape, or surface cover are stopping enough light from reaching a carpet or shorter plants below.

I was nervous about getting my deposit back the first time I hired one, but I had no problems at all. A friend of mine also hires them regularly to test his marine aquarium lights without issue.

The Bacteria that Can Complete the Aquarium Nitrogen Cycle Alone!

📖 My Accompanying Article For This Video → https://glassboxdiaries.com/beneficial-aquarium-bacteria/

🛒 Aquarium Equipment I Use & Recommend → https://glassboxdiaries.com/accessory-index/

🌿 Find The Right Plants For Your Aquarium → https://glassboxdiaries.com/lowtechplantindex/

🐠 Browse All Of My Aquarium Care Guides → https://glassboxdiaries.com/care-guides/

Researchers discovered a type of bacteria in 2015 that completely changed our understanding of the aquarium nitrogen cycle.

They're known as Comammox bacteria, short for "complete ammonia oxidation", and they have a particularly interesting ability that could make them an important part of mature aquarium biofilters.

The traditional explanation of the nitrogen cycle is that one group of microorganisms converts toxic ammonia into nitrite, then another group converts nitrite into nitrate.

Comammox bacteria can potentially do both jobs themselves, converting ammonia all the way through to nitrate without relying on a separate group of nitrite-oxidising microorganisms.

Research also suggests that Comammox bacteria can remain active across a surprisingly wide range of pH levels, temperatures, oxygen concentrations and water hardness. This adaptability could help explain why they've been detected in so many different environments.

However, they do have one major limitation: they grow relatively slowly.

Because of this, Comammox bacteria aren't necessarily the microorganisms that dominate during the early stages of cycling a brand-new aquarium. Instead, they appear particularly well suited to mature environments where ammonia concentrations remain consistently low.

Several studies have found that Comammox bacteria can become important, and sometimes dominant, nitrifying microorganisms in established biofilters.

This means the microorganisms responsible for keeping an aquarium stable may be more diverse than the simplified nitrogen cycle diagrams we've been using for decades suggest.

You don't necessarily need to buy bottled bacteria to introduce Comammox to your aquarium either.

They appear to be widespread in nature and may naturally enter our tanks through live plants, livestock, substrate, hardscape and potentially even tap water in some areas.

They might not be the first nitrifiers to establish themselves in a new aquarium, but given enough time, Comammox bacteria could become an important part of the biological filtration quietly processing waste and helping maintain safe water conditions.

How To Remove Tannins From Aquarium Water!

Tannins turning your aquarium water yellow or brown? Here are a few easy ways to reduce tannins and keep your aquarium water looking clearer.

🛒 Aquarium Equipment I Use & Recommend → https://glassboxdiaries.com/accessory-index/ 🌿 Find The Right Plants For Your Aquarium → https://glassboxdiaries.com/lowtechplantindex/ 🐠 Browse All Of My Aquarium Care Guides → https://glassboxdiaries.com/care-guides/

Tannins are naturally released by many types of driftwood, leaves, seed pods and other botanicals. They aren't necessarily bad for your aquarium, and some fishkeepers actually prefer the darker blackwater look, but it isn't for everyone.

If you want clearer water, prevention is usually easier than trying to remove tannins later. Choosing low-tannin driftwood and botanicals can make a huge difference.

In my experience, spider wood releases relatively few tannins compared to many other popular types of aquarium driftwood. Mulberry leaves and cholla wood are also good options if you want to add natural materials without heavily staining the water.

Magnolia, oak and catappa leaves can release more tannins, but pre-boiling them before adding them to the aquarium can help remove some of the initial tannins and reduce how much they stain the water.

If your aquarium is already brown, regular water changes are one of the easiest solutions. Each water change physically removes some of the tannins and replaces the stained water with fresh water.

The problem is that materials such as bogwood and alder cones can continue releasing tannins for months or even years, so water changes aren't always a permanent solution.

Activated carbon can help remove tannins and is relatively affordable, but it can also adsorb some trace elements, including copper, iron and zinc. This may make it less desirable in heavily planted aquariums.

Purigen is another option. It usually costs more than activated carbon, but it's less likely to reduce micronutrients and can be regenerated once it becomes exhausted, potentially making it more economical over time.

Or you can simply wait.

Why My Mystery Snails Started Eating My Aquarium Plants!

I thought my new mystery snails were destroying this planted aquarium... but it turns out the real problem was me.

After only a month in the tank, they'd completely eaten my Lobelia cardinalis 'Mini' and Pogostemon helferi, heavily damaged my Staurogyne repens, and even started working their way through my Bacopa compact. At first, I assumed I'd discovered that mystery snails simply couldn't be trusted with live plants.

The strange thing is that I'd kept nerite snails and ramshorn snails for years without ever seeing this kind of damage, so something didn't add up.

The answer ended up being my fish.

My golden White Cloud Mountain Minnows have always left algae wafers alone after taking a quick look, allowing the shrimp and snails to feed. I assumed my regular White Cloud Mountain Minnows would behave the same way, but they don't. They rush straight over, eat as much of the algae wafer as possible, and leave almost nothing behind.

That meant the mystery snails weren't getting enough food. Rather than being "plant-eating snails", they were simply hungry, so they turned to the only reliable food source left in the aquarium: my plants.

After trying several different ideas, two friends suggested offering boiled or blanched vegetables instead. Sweetcorn was completely ignored, but green beans were an instant success. They've also happily eaten peas, carrots and bell pepper, while the White Cloud Mountain Minnows have shown almost no interest, allowing the snails to feed in peace.

It's now been a week since switching over to vegetables, and the damage to my Staurogyne repens has stopped completely. It's still early days, but it looks like making sure the mystery snails have their own dedicated food source may have solved the problem.

Here's a quick update on my 25-litre Walstad-style Medaka aquarium before the full one-year update goes live.

Unfortunately, I recently lost one of my male Platinum Medaka. He was the oldest fish in the tank, and with heated aquariums typically limiting their lifespan to around two years, but I think it was old age rather than illness.

The females have been laying eggs on several plants over the past month, although I haven't spotted any fry yet.

The mixed-bloodline ("mutt") Medaka has also started developing a slight spinal deformity, but as none of the Platinum Medaka show the same issue, I suspect it's genetic rather than disease-related.

The tank is also home to a Skittles colony of Neocaridina shrimp. Most of the orange, yellow and blue shrimp have gradually reverted to their wild-type colours over the generations, while the reds have held their colour well.

After moving a lot of them into my 70-litre aquarium, the remaining colony has exploded thanks to the warmer summer temperatures, so I'll soon have plenty more shrimp to stock future tanks.

Plant growth has been excellent. The Pogostemon quadrifolius has become the real workhorse of the aquarium, growing so quickly that it could probably keep the tank stable even without a filter by absorbing excess nutrients.

I removed the Rotala Blood Red varieties because constantly trimming and replanting stem plants became more effort than they were worth in a Walstad aquarium, replacing them with fresh Pogostemon trimmings that are already filling in nicely.

The Helanthium tenellum 'Green' carpet is also progressing well, especially considering it's growing under an entry-level Seaoura SR616 light.

A stronger light or planting a few extra pots from the start would likely have produced a full carpet by now, but I'm still really pleased with how it's developing.

A Quick Update On One Of My Filtered Walstad Method Planted Tanks!

Here's a quick update on my 375-day-old Walstad method Medaka aquarium! The full one-year update will be coming to YouTube soon, but I wanted to give you a look at how the tank is progressing after more than a year of running with a low-maintenance approach.

This is a 25-litre (6.6 US gallon) planted aquarium running a Nicrew Slim hang-on-back filter, an Eheim Jager heater, and a Seaoura SR616 LED light. Sadly, I recently lost one of my oldest Platinum Medaka, but at around two years old, I believe it was simply old age rather than illness.

The remaining Medaka are doing well, and I've been seeing the females laying eggs on the plants over the last month. No fry have appeared yet, but hopefully it's only a matter of time. One of my mixed-breed "mutt" Medaka has developed some spinal deformities, although none of the Platinum Medaka show the same issue, so it looks more like a genetic problem than a disease.

The tank is also home to a Skittles colony of Neocaridina shrimp. Interestingly, only the red shrimp have consistently held their colour, while the orange, yellow, and blue shrimp have gradually reverted back towards the wild type. I recently moved a large number into my 70-litre aquarium, but the warmer summer temperatures have triggered another breeding boom, so this tank is quickly filling up again.

Plant growth has been excellent. I replaced the Rotala Blood Red varieties with Pogostemon quadrifolius because it's much easier to maintain in a Walstad aquarium, and the new cuttings are already starting to establish. The Helanthium tenellum 'Green' carpet is also coming along nicely despite using an entry-level light. With a stronger light or more plants at the start, it probably would have filled in much sooner.

Java Fern vs Bucephalandra: Which Is Better For A Low-Tech Planted Tank?

Java Fern and Bucephalandra are two of the most popular plants for low-tech planted aquariums, but despite both being epiphytes, they serve very different purposes.

In this comparison, I break down the biggest differences between them to help you decide which is the better fit for your aquarium. Both plants are normally attached to rocks or driftwood instead of being buried in the substrate, making them easy to add to most aquascapes, but that's where many of their similarities end.

Java Fern is the larger of the two, often reaching around 30 cm (12 inches) in height. It develops broad, dense clumps of leaves that create excellent hiding places for fish while also acting as natural sight breaks that can help reduce aggression in community tanks.

Bucephalandra stays much smaller, with many varieties growing to around 5 cm (2 inches). Instead of creating large masses of foliage, it's usually used to add detail, texture and colour to hardscape. One of its biggest advantages is the huge range of leaf shapes and colours available, with many varieties displaying attractive red, bronze and brown tones even under affordable LED lighting in low-tech aquariums.

Although both plants are often recommended for beginners, neither is completely maintenance-free. Java Fern can be more demanding in certain water parameters than many people expect, while some Bucephalandra varieties can struggle in hard or very hard water. Understanding your own tap water can make a big difference when choosing between them.

If I could only keep one, I'd choose Bucephalandra. Larger Anubias plants already provide plenty of cover and sight breaks in my aquariums, so Bucephalandra fills a unique role that I find much harder to replace. Its compact size, slower growth and incredible variety make it one of my favourite plants for adding detail to planted tanks.

The Easiest Way To Grow Aquarium Plants Faster!

How the fish poop fertilization method works - https://glassboxdiaries.com/fish-poop-fertilizer/

Want faster plant growth in your planted aquarium without immediately reaching for fertilisers? One of the easiest changes you can make might be something you're already doing every day: feeding your fish.

A lot of hobbyists focus on buying stronger lights, adding CO₂ systems, or constantly changing fertilisers, but sometimes the limiting factor is simply that there aren't enough nutrients being added to the aquarium in the first place. That's especially common in low-bioload tanks with species like bettas or shrimp, where very little food is going into the system.

I'm not suggesting you suddenly double the amount you feed your fish. Instead, a small increase in feeding can provide more nutrients for your plants through the natural waste produced by your livestock. It's a simple approach that I've been using in several of my own aquariums after moving away from liquid fertilisers, and the results have been surprisingly consistent.

I have a full article on my website covering the fish poop fertilisation method in more detail, but the basic idea is that fish waste eventually breaks down into nutrients that aquatic plants can use. As organic waste decomposes, it can also contribute a small amount of natural CO₂, giving plants another potential source of carbon in low-tech aquariums.

Of course, lighting, plant selection, water parameters, and CO₂ availability still play major roles in plant growth, so this isn't a magic fix for every tank. However, if your aquarium has a healthy balance already, slightly increasing feeding can sometimes be enough to noticeably improve growth without buying additional equipment.

One easy way to monitor how your aquarium responds is by using a liquid test kit to check your nitrate level. Nitrate is one of the main macronutrients aquatic plants use, and in my own planted tanks I've consistently seen stronger growth when nitrate stays around 10-20 ppm compared to tanks that remain below 10 ppm.

As always, avoid overfeeding. Only increase feeding gradually and make sure your fish consume most of the food you add. If you're worried about leftovers, shrimp, snails, and other clean-up crew members can often help consume uneaten food before it has a chance to cause problems.

The Water Change Myth Everyone Believes!

One of the biggest myths in the aquarium hobby is that large water changes are always dangerous. In reality, it's not the percentage of water you change that matters most, it's how closely the new water matches the water already in your aquarium.

In this video I explain why the common "25% water change every week" recommendation isn't a universal rule. While there are situations where changing around 25% makes sense, such as gradually reducing nitrate levels, many people repeat the advice without understanding why. Over time, that has led to the misconception that anything larger will automatically shock your fish.

The truth is that many aquariums can safely handle much larger water changes when they're done correctly. Matching the temperature of the new water, using a dechlorinator, and making sure key water parameters are reasonably similar can make a huge difference.

In my own heavily planted aquariums, the Total Dissolved Solids (TDS) stay surprisingly close to my tap water because the plants help maintain stable water conditions. That means I can perform larger water changes when needed without causing problems. Every aquarium is different though, so it's always worth checking your own parameters rather than relying on general advice.

Affordable tools like a TDS meter, digital thermometer, pH meter, GH/KH test kit, and a standard aquarium liquid test kit can help you compare your aquarium water to your tap water before carrying out larger water changes. Spending a few minutes checking your parameters is far more useful than blindly following an old rule that may not apply to your setup.

The goal isn't to encourage everyone to do massive water changes. It's to show that one larger water change can often be a perfectly reasonable option if your schedule doesn't allow for several smaller ones. Understanding why you're changing water is far more important than sticking to an arbitrary percentage.

This Budget Light Grew An Aquarium Carpet!

One of the biggest myths in the planted aquarium hobby is that you need an expensive aquarium light and a pressurised CO₂ system to grow a healthy carpet. While those things can certainly help, they're far from essential if you choose the right plants for your setup.

The light I'm Using - https://glassboxdiaries.com/seaouralight (Affiliate Link, I Get Commissions)

The Plant I'm Growing - https://glassboxdiaries.com/plant/helanthium-tenellum-green/

Other Low-Tech Carpeting Plants - https://glassboxdiaries.com/lowtechplantindex/plant_type-carpeting/

This aquarium is running a very affordable Seaoura SR616 LED light with no CO₂ injection at all, yet it's still supporting a carpet alongside the rest of the plants in the tank. The light has been running at maximum intensity, and during the time this carpet has been growing I've experimented with both 6-hour and 12-hour photoperiods with good results.

The carpeting plant you're looking at is Helanthium tenellum 'Green', which I genuinely think is one of the easiest carpeting plants available for low-tech planted aquariums. It's much more forgiving than many of the popular carpeting species people recommend online, making it a great option for beginners or anyone trying to keep costs down. I've also put together a full care guide for it on my website for anyone who wants more detailed information.

The carpet is still a little patchy, but that's completely expected. In hindsight, I could have planted another one or two pots when I first set the aquarium up, and it would have filled in much faster. Given enough time, though, it will continue spreading naturally through runners.

For me, this tank proves an important point. Success in planted aquariums isn't always about buying the most expensive equipment. In many cases, choosing plants that naturally suit your lighting, water parameters, and maintenance routine will give you far better results than simply throwing money at the problem.

There's often far too much focus on high-end lighting, CO₂ systems, and expensive substrates, when many beautiful planted aquariums can be created using budget-friendly equipment and carefully selected plant species. Understanding what each plant actually needs is usually far more valuable than chasing the latest gear.

125-Day Planted Aquarium Update (Inert Sand, No CO₂, No Root Tabs)

This is my 70-litre (18 US gallon) planted aquarium, now 125 days old and home to two honey gouramis, nine lambchop rasboras, and a colony of mixed-line Neocaridina shrimp.

The tank uses inert sand with no root tabs, a Seachem Tidal 35 filter, and a Chihiros B Series light. I moved the honey gouramis over a couple of weeks ago, and they've settled in perfectly. One has claimed the back left corner, the other the back right, and one has already started building a bubble nest.

The lambchop rasboras are doing well too, and I'm thinking about increasing the group soon. I was originally considering adding Panda Corydoras, but I'm now leaning more towards moving my ember tetras and pygmy corydoras over from another aquarium instead.

The "Skittles" Neocaridina colony originally included red, orange, yellow, and blue lines. Apart from the reds, most have gradually lost their colour over time, although they still produce some really interesting wild-type shrimp.

Overall, I'm really happy with how the plants are progressing. I recently added an Echinodorus 'Aflame', which is supposed to be an easy red sword plant, so it'll be interesting to see how it performs over the coming months.

The standout plant has to be the Aponogeton ulvaceus. Most nurseries recommend growing it in a nutrient-rich substrate, yet it's thriving in plain inert sand and has already produced both runners and a flower.

Several other plants that are usually considered heavy root feeders are doing well too, including all of the Cryptocoryne species and most of the Echinodorus swords, although my Echinodorus 'Tricolour' is still taking its time.

The houseplants are starting to fill in nicely as well, with spider plants, Epipremnum, and Philodendron all taking advantage of the warmer summer weather.

The only real challenge at the moment is algae.

I'm fairly sure it's being fuelled by excess organics released as the Centurion wood decomposes, but thankfully it's gradually becoming less of an issue as the tank continues to mature.

PLANT LIST

125-Day Planted Aquarium Update (Inert Sand, No CO₂, No Root Tabs)

This is the latest update on my 70-litre (18 US gallon) planted aquarium, now 125 days old, and I'm really happy with the progress it's made so far. The tank is home to two honey gouramis, nine lambchop rasboras, and a mixed-line "Skittles" colony of Neocaridina shrimp. Despite using inert sand with no root tabs, the aquarium continues to grow a wide variety of plants surprisingly well under a Chihiros B Series light with filtration provided by a Seachem Tidal 35.

The honey gouramis only moved into this aquarium a couple of weeks ago, but they settled in almost immediately. One has claimed the back left corner while the other has taken over the back right, and one has already started building a bubble nest. The lambchop rasboras are thriving too, and I'm considering increasing the size of the school. I originally planned to add Panda Corydoras, but I'm now leaning towards moving my ember tetras and pygmy corydoras into this aquarium instead.

The mixed-line Neocaridina shrimp are still breeding well. The colony originally included red, orange, yellow and blue shrimp, although apart from the reds, many of the other colour lines have gradually faded over time. Even so, they continue to produce some really interesting wild-type shrimp with unique patterns and colours.

One of the newest additions is an Echinodorus 'Aflame', which is often recommended as an easy red sword plant. It'll be interesting to see how it develops over the coming months. The real star of the aquarium, though, has to be the Aponogeton ulvaceus. It's commonly recommended for nutrient-rich substrates, yet it's thriving in plain inert sand, producing long flowing leaves, runners, and even a flower.

Several plants that are usually described as heavy root feeders are also growing far better than many people would expect. The Cryptocoryne species and most of the Echinodorus swords are doing extremely well, although the Echinodorus 'Tricolour' seems to be growing more slowly than the others at the moment.

The emersed houseplants are beginning to fill in nicely too. The spider plants, Epipremnum, and Philodendron have all put on noticeable growth as the warmer summer weather has arrived, helping to create a more natural riparian look above the aquarium.

The biggest challenge right now is algae. I'm fairly sure it's being fuelled by excess organics released from the Centurion wood, which started decomposing much faster than I expected after it was added to the tank. Thankfully, the problem is slowly fading as the aquarium continues to mature.

I Removed My Guppies… Everything Changed (Planted Aquarium Update)

What happens when you remove the main predator from a planted aquarium? That's exactly what I'm finding out after taking the guppies out of one of my tanks and giving them to a friend for his breeding project.

Within just a couple of weeks, the ecosystem has already started changing in some really interesting ways. The biggest difference has been the sudden explosion in the flatworm population. Although they look similar to planaria at first glance, I believe they're harmless flatworms because their heads have a different shape. It seems very likely that the guppies had been quietly controlling their numbers without me ever noticing.

I've also seen a huge increase in what I believe are freshwater copepods, although I'm not completely certain of the identification. Whatever they are, their population has grown dramatically since the guppies were removed, suggesting they were another natural food source that the fish had been keeping in check.

Freshwater limpets are still present too, although I haven't noticed any significant change in their numbers just yet. It'll be interesting to keep watching over the coming weeks to see if they also respond to the absence of the guppies.

The Neocaridina shrimp continue to thrive as usual. Despite keeping guppies with them for years, I've never actually witnessed the guppies eating either adult shrimp or shrimplets. Even so, I'm curious to see whether the shrimp population grows more quickly now that one potential predator has been removed from the aquarium.

Of course, ecosystems are always changing, and this experiment probably won't stay this way for long. I've recently introduced medaka ricefish fry into the tank and, as they grow, they'll almost certainly begin feeding on some of these tiny invertebrates. That should shift the balance of the aquarium once again and create an entirely new food web.

It's a great reminder that every species in an aquarium influences the ecosystem, even in ways we don't always notice. Sometimes removing just one fish can trigger a chain reaction that affects countless other organisms living in the tank.