Filter Redunancy

[Gelt]

Hey ,

Just waiting for my tank to arrive, have a question regarding dual filters during fishless cycle


Fluval Roma 125L (33 US Gal) - i want to do a bit of forward planning and run a smaller internal filter (about 60L spec ) alongside my Fluval U3 , my theory is that i will then have (eventually!) a smaller filter in case of main filter brakedown and to run a smaller hospital tank as and if required.

i have a donation of mature media from a 300l tank in place when i call and will kick start both filters, starting both on Day 1 fishless cycle.

first question ....if my 125 is cycled with both filters and one is removed after stocking , how will this affect the water chemistry and will it cause any short term issues?


Tank setup:

Fluval Roma 125 (est delivery in 3 days)
heater (spare already purchased)
2 x thermometer ( digital and glass)
2x hood lights day glow
pump and airstone for use when cycling

sand substrate (to be washed, currently dry and bagged) 20kg
mopani wood centre piece ( tanins removed , has been in soak 24/7 for two weeks)*declorinated water*
purple slate rocks (scrubbed and boiled, in soak for 3 days)*declorinated water*
* No cheesy ornaments or signs*
Will be lightly planted , with ample foliage cover, making up with silk plants.

oh and the usual API master liquid test kit and first aid bag ..basic meds
Declorinator, bicarb, Ammonia , syringes , droppers and bottles. Not to mention siphon vac and usual tools of the trade.

Stocking: * Anticipated* - Not even getting within a mile of the tank till Fishless cycle done !
12 cardianls
12 Harlequins
6 cory
3 ottos

Um did'nt mean to ramble on, only wanted to ask one question...thanks in advance.

 

[Gvilleguy]

Hi Gelt - the media in both filters will split the load of the fully cycled tank. So, therefore, the larger filter will not have as much bacteria after the cycle as it would had it cycled on its own. So, yes, after you cycle the tank with both filters, if you remove the smaller one, this will have an impact on the tank, and might cause it to mini-cycle, depending on what overall % of media you are removing. A newer tank would be more likely to enter a mini-cycle versus a more mature tank.

However, I have read numerous posts from forum users that keep a small filter on their tanks to use as needed on their quarantine tanks, and they do not seem to have trouble.

 

[waterdrop]

I think the more lopsided the filter sizes the easier it will be to remove the small one for a task without the tank going into spikes. As long as you don't fully or overstock it's unlikely you'd have much trouble with the combo you describe. Of course, it would be necessary to be testing as you did something like that and stand ready to do water changes if you saw ammonia or nitrite.

~~waterdrop~~

 

[anon02]

If your fluval filter comes with carbon you could replace it with bio media then you would always have cycled media in the event that you needed to set up a q tank

 

[Gelt]

Thanks for the advice guys, i think i'll remove the carbon and add sponge as a sort of extra supply for a hospital tank if required.