No problem! I’d suggest shopping around and finding what the cheapest options are for you, as it may depend on what you can find locally or what you can get free shipping on, as well as the price of these products.

Drainage layer options:

Zoo Med Hydroballs

Exo Terra BioDrain

Hydroton Hydroponic Grow Rock

Growstone GS-1 Hydro Stones

LECA (lightweight expanded clay aggregate)

NEHerp LDL (lightweight drainage layer)

Josh’s Frogs False Bottom

TheBioDude Drainage Layer

Egg Crate

Gravel

Some of the hydroponics materials may be cheaper since they are not aimed at animal keepers.

If you absolutely can’t afford another drainage layer material, gravel is possible. You can use aquarium gravel. However, gravel is extremely heavy, and also doesn’t have capillary action which the other, porous drainage layers do.

Here is how to create a simple egg crate false bottom: (Page One, Two)

Here is a more complex build incorporating PVC pipe supports.