i am currently cycling my 5 gallon and in a few months ( after we move) i plan to establish a second tank by running the second filter in my current tank. how long will the filter need to be in the established tank before i can safely put it back in its own tank and add fish?
Also will it affect the already established tank?
40 gallon - Misc fish
15 gallon - Axolotl
5 gallon - Betta and ADF
20 long - Hatchling turtles and corydoras.
Honestly there is very little bacteria in the water column so there is no need to transfer the old tank water to the new tank. Transferring rocks and substrates to the new tank is the better solution. You should run the 2nd filter about a month to get it seeded. Always check for water parameters after moving things between tanks.
Yes you can move the snail over. Take some gravel from the firs tank and put it in a filter media bag or a clean pantyhose and drop it in the second tank. That way you won't be mixing different color gravel.
There is bacteria in the water column.......
Aquarium Aerobic Bacteria and Anaerobic Bacteria are in the water column. They is more bacteria in the filter and gravel but it also found in the water column.
No one said there wasn't bacteria in the water. It is minimal at best. If you want to seed a new tank, you need to use gravel, decorations or filter media from an established tank (best option). If you use just the water from the old tank in the new tank, that bacteria will die off before it starts to grow. You will basically be starting from scratch.
Just take the filter media (part or all) out of the 1st filter and put it into the second filter...assuming that's possible with your filters. Your 1st filter will regrow bacteria just as it would when you replace media during maintenance. This will make your 2nd filter usable immediately.
Your idea of running both filters in the original tank will work too, but I'd give that 1-2 weeks.
I've used both methods and prefer moving the media because it's faster and easier.