The Puffer Forum

Ohk hypothetically speaking if you had a 20g and you wanted to up it to a 40g could you just transfer the water out of the 20g to the 20g and add another 20g of freshwater? Just a hypothetical I was pondering earlier

To have it cyled do you mean????

No I mean add 20g of cycled water to a 40g tank and then add 20g of fresh water that has been conditioned to it so wouldn't it be like a 50% water change?

There is a massive difference between "cycled" and "conditioned". Which are you asking about?

Conditioned water has had the disinfecting agents (used by the water utilities to protect water and keep it potable during and after transit to your house) neutralized or removed. It is, after conditioning and tempering, fish-safe. But it is not cycled.

A cycled tank has a mature biofilter capable of detoxifying the nitrogen wastes of livestock in the tank.

Conditioning is a one-time process for each batch of water. Cycling is a bacterial process handled by the bacteria in a filter or in live rock. It is on-going for the life of your system.

So, which are you asking about?

It doesnt make sense why you would want to add polluted water in an upgraded tank. As long as you add the old filters or media you don't need to

In theory, yes--this will be just like doing a 50% water change & is how I upgrade my tanks. But you also must move over ALL the substrate, decor & filtration, too. The nitrification bacteria lives on the surfaces of these things. There is no such thing as "cycled" water.

Gotcha! Thanks PP! That is the kind of answer I was looking for!

But it would be all right to do something like that?

as long as you move everything over it will be fine.

just don't any additional live stock than what is already there in the 20 gal. The biofilter is set for the output of the inhabitants of the 20 and no more. Adding it to the 40 doesn't change that right away. Keep the current stocking and like PP said, move everything over.

If you are moving decor, substrate and filtration i feel there is no need to add used water. Just run for a hour or so as you introduce fish. I never add used water to a setup just used filters etc. What works for one may not be ideal for another, not trying to say what pp says is wrong (she has more experience than me) but i use a different method which also causes no issues. Its down to u really

use of the old water is more personal choice, but the water perams will be closer to the original with 50% original water.

So I can use "used" water or I can use the filter with new water?

So if were to set up my 225g with my old filter off the 40g it would be ready in few hours?

I just want to make sure that I am understanding this

You have two different takes on this you need to make the choice. I would add all the stuff from the old tank including media into the new filters. Then acclimayise fish into new water. Others would use used water. 40g of used water in a 225 is not 50% so ..................... Its upto you

You could...

it would still work. Just match the the temp and if possible the pH.

Yeah I know 40g isnt anywhere near 50% of a 225g. It was just a question to help my deeper understanding of what is right and wrong

As far as preference goes nothing is right or wrong. You can only do what you feel is best. Just acclimatise to new tank as if it was a new fish and you will be ok. Whatever you chose