BB only exist in enviorments favorable for existence. Its not very hard to accommodate them, all they need is food and somewhat consistant water conditions. The will only proliferate to the point where no more food is left over to support higher numbers. When you think about it fry produce a very light bioload so you don't need to have to tank ready for a heavy stocking of large fish you just need to supply a small amount of BB to take care of the light bioload. As the fry grow the bacteria colony will grow with them. As more food for them becomes available their numbers will grow to handle it. So there are several ways to do this but almost all include moving bacteria from your established tank. You can put the sponges in the 75 for a week or two, you can add some floss to the filter for a few weeks then remove it cut it up and drop it in the fry tanks, you could ring out your filter media in the new tanks......there is countless different ways but the principal is that the BB grow on anything with surface area they cover the whole tank and filter so add surface area to the host tank then remove it and put it in the new tanks. In between periods where the tank is empty you have two options either supply food for the existing bacteria or remove surface area put it back in the main tank until you are ready to use them again and return it.
Sent from my SCH-S960L using MonsterAquariaNetwork App
