stores underrate DIY co2
by a ton, and overrate aquarium additives like tap water and test kits.
usually i steer clear of testers, but when i added DIY co2
i gave in and purchased a small device that sat on the inside of the tank with liquid in it, to tell me the level of co2
. after a mere 3 months the suction cups didn't work anymore, and that was made by a high-ranked company.
thankfully i have a snail infestation atm, so when there's 15 snails heading up the glass towards the surface i know that i have to ease the co2
level a bit.