No. Or at least not in any quantity that would make it relevant in most cases. Some bacteria undoubtedly grow there, as it will on most surfaces. But the majority of the beneficial bacteria will be in your filter media.
PVC just stands for PolyVinalChloride, a type of pipe that is fairly non toxic to fish. It can be used in plumbing with aquariums, or as is mentioned as 'cave' material. You can't use metal with aquariums, as it is toxic, so PVC is used.
Land of the Midnight Sun 8)
only for hiding place..
have u guys ever breed guppies? I just had at least 30 babies ...since I have no extra tank ( had 1 main aquarium where all my platty, tetras, guppies and swordtails live peacefully, another for breeding purpose) , I just put them together with my 1 1/2 wks old white swordtail babies and 1 wk old molly babies.
Will they be safe since they are much much more smaller than the 2 types.
Feed them normal flakes I bought ..do they really eat?
for our baby platys, we put a bunch of flakes in a plastic baggie and crushed them to powder with a rolling pin, then would feed them pinches of powder.