Filter Question

[ChiaJesus]

In my 150G I have two filters: a Fluval FX5 and a Rena Filstar XP4. Both have been on there for a few months and obviously everything is cycled nicely.

Today I'm starting up a new 125G and bought one FX5 for it. Would it be OK to hook up the new FX5 to my 150 and move the already-cycled FX5 to the new 125? Or would it be better to just take some media from the old FX5, add it to the new one, and do a fishless cycle?

My gut tells me it would be OK to move the old FX5 to the new tank and just get going but I thought I'd ask the experts first.

[jm1212]

either would be ok, but the best idea would be to take some media from the old FX5 and some old media from the XP4 (something universal...like carbon) and put them in the new FX5

[irishspy]

:iagree:
I'd take some media from both and use it to seed the new filter.

[excuzzzeme]

For the effort involved it is easier just to move one of your filters. Moving media is having the same effect as moving a filter. Since you are moving only 1 of 2 FX5's there should be no impact to the cycled tank. I often move a piggy-backed or secondary filter from established tank to another tank. Moving some water and substrate if possible would help also.

[ChiaJesus]

Perfect. I should have guessed that there was an option #3. Thanks!

[excuzzzeme]

I moved water, substrate, and a filter from a 55 to a 90 (upgrade). This was the same as doing a 50% water change. I added fish the same day as it was already up to temp. No stress to the fish involved. In this case I would carry over about 50 gallons to assist in the cycle. Due to the tank size, and water volume, I would add fish same day and just do a PWC every 3 days for about 2-3 weeks (unless you are moving sensitive fish).

[THE V]

I agree that you can just move one filter to the new tank and put the new on on the old one. Remember you can remove up to 50% of the bacteria in the tank and have the numbers back up to normal in 24 hours.

You can also stock the new tank up to the same level as the first on the same day as well.

BTW two tanks that size? Unfair.... I've only got my 125.