LocalAquarist

So, I'm preparing to make a planted tank for some guppies I want to get in the next few months. They prefer a more basic pH for water and right now I'm trying to figure out how to make water more basic. In class we learned that an increase in carbon dioxide leads to ocean acidification, which I can also assume increases the acidity of other water. I am getting liquid CO2 to start of the tank, since I won't have anything living in there for a while. But I can assume that if I add enough CO2 into the water, it will lower the pH, which is what I don't want. So, I need to find a way to balance the added CO2 with something that makes the water basic. There are recommendations of using baking soda to make the water more basic but the problem with that is baking soda is made with sodium and will increase the salinity of the water. Another I saw was using Cuttlebones, which I do have on hand and are relatively cheap to get compared to limestone and crushed coral. I was going to run a proper experiment that would've been in a pitcher but decided not to because I was resetting my tank anyways since I moved back home. So, my tap water is 7.0 and I wanted it to be 7.6 for my betta Kimchi. I got a cheese grater that we don't use and start shredding the cuttle bone into dust, including the outside that I found out should have just been thrown out. If you are doing this THROW OUT THE OUTSIDE SHELL, it's not hurting the fish, he's fine but it says to not feed to the bird so preferably you don't want that in the tank. I threw the dusted cuttle bone into the tank and the pH started to rise, it was now at 7.2. It didn't take a lot for the pH to finally reach my goal of 7.6.

I actually found an article that demonstrates what I am doing and explains some things about cuttle bone, so I will be linking it here. You could use eggshells instead because they are both made of Calcium Carbonate (CaCO3). But because of its structure it is less soluble, so maybe use it for a gradient filter? But I am not sure how those work fully yet to be completely honest. Just keep it away from the fish where the sharp edges won't reach them, either from floating in the water or the fish investigating the shells.

The article says you can put in the cuttle bone it's self in the tank without dusting it to prevent pH drops. Which actually might be easier than my method. For me I do a water change every other day right now because I am lacking real plants; I have fake fabric ones. So when I do a water change, I make sure the new water I am putting in is the same or really close to the pH of the tank by throwing in the cuttle bone dust in there, stirring, and letting it sit for a little.

I don't want to stress my fish out by fucking around and finding out that putting 7.0 water into 7.6 water makes it crash. With or without a big ol' cuttle bone in there.

To conclude you can use almost anything that has Carbonate (CO3) in the chemical formula. BUT you need to check what it is bonded with and other ingredients that are in it. You could technically use baking soda (NaHCO3), but it has sodium in it which will increase your waters salinity. Do not use this, please. For freshwater fish they don't need a salinity, then for saltwater fish you're already trying to get the perfect balance salinity, and this is just going to make it imbalance unless you know exactly what you're doing. I don't deal with seawater fish, and I'm not trying to kill fish I don't know how to care for during uni. But that is my warning.

WHEN USING ANYTHING WITH YOUR TANK CHECK THE INGREDIENTS; CHECK THE CHEMICAL FORMULAS.

Material Master List: ($11-19) ✦ Cuttlefish Bone 2 pack ($2-5) *Says for birds. You can also find bigger packs for cheap. ✦ Api pH Test Kit ($7-8) ✦ Cheese Grater ($2-7) *Not necessary. You can scrape dust easily with your nails.