Need advice please!

Tank26 · Sep 25, 2019

Good morning,

I am new to the site and very happy a friend gave me the info. I am looking for advice on my recent change from a Fluval FX6 (yes I learned canister filters suck) I set up a 120 gallon FWLR tank about 2 years ago. With advice from my local fish store I purchased a Fluval canister lower model which has lead to fighting Nitrates since the tank set up. Main reason was the stand that came with the tank was not built to house a sump. I then upgraded and purchased the Fluval FX6 after being assured it would help by my LFS. Which still did not help the nitrates even after spending an additional $400.00.

So after meeting some really cool people in the hobby and losing tons of money on beautiful fish, I decided to build a new stand and convert to a 30 gallon sump with refugium. The sump has been running for 24 hours and seems to be doing great! (why didn't I do this to begin with) Currently I am waiting on delivery of my internal Reef Octopus skimmer rated for 200 gallons or better, but have a hang on back Reef Octopus skimmer that I have been using for about 6 months. I have roughly 80-90 pounds of live rock and the tank is stocked lightly. I also DO NOT overfeed before that question comes up. lol

My question is when can I remove the Fluval FX6 canister filter now that the sump is up and running with the refuguim. I feel the canister is the problem and a Nitrate factory, but I want to avoid a mini cycle and any other problems before going to the sump completely.

Current parameters:
Salinity-1.022
PH-8.2
Ammonia-0
Nitrite-0
Nitrates-off the chart!

Thank you in advance for your advice!

foxt · Sep 25, 2019

Unless I am missing something, you should be able to shut the cannister down right away.

Maybe a few questions: what is in the cannister? Any chemical filtration, or just media for bacteria and filtering? Will/has the flow that it was providing be replaced by a return from the sump?

The biofilter lives in your rock, substrate, on the surfaces of other stuff, and shutting down the cannister won't affect the ability of your tank to treat ammonia.

vetteguy53081 · Sep 25, 2019

The sump is chemical filtration and canister would be mechanical. You can use canister to run carbon and other media such as phoszorb or disconnect cannister and keep it to polish water occasionally

Brandon Smith · Sep 25, 2019

I agree with the other two. There shouldn't be no reason why can't just shut the canister filter off now.

Tank26 · Sep 25, 2019

foxt said:
Unless I am missing something, you should be able to shut the cannister down right away.

Maybe a few questions: what is in the cannister? Any chemical filtration, or just media for bacteria and filtering? Will/has the flow that it was providing be replaced by a return from the sump?

The biofilter lives in your rock, substrate, on the surfaces of other stuff, and shutting down the cannister won't affect the ability of your tank to treat ammonia.

Hi Brandon,

No chemical filtration with the FX6 canister, just standard filtration sponges. The sump has a return pump rated for 1200 gallons an hour and good flow. Also run 2 Hydor Koralia Evolution pumps for added flow.

Just wanted to confirm no issues with removing the canister.

Thank you!

Florida Sunshine · Sep 25, 2019

It depends if there is filter media somewhere else. Does your tank have live rock? How much? As long as there is sufficient live rock the bacteria will live there and you can just disconnect or turn off the canister filter.
You can keep it as part of your filtration if you like. The problem with canister filters is that few people keep them properly cleaned. If you are willing to put in the work to clean/replace media frequently it becomes a nitrate dump.
As far as a recommendation going forward I would do an immediate 50% water change to get the nitrates a boost out the door.

Tank26 · Sep 25, 2019

Florida Sunshine said:
It depends if there is filter media somewhere else. Does your tank have live rock? How much? As long as there is sufficient live rock the bacteria will live there and you can just disconnect or turn off the canister filter.
You can keep it as part of your filtration if you like. The problem with canister filters is that few people keep them properly cleaned. If you are willing to put in the work to clean/replace media frequently it becomes a nitrate dump.
As far as a recommendation going forward I would do an immediate 50% water change to get the nitrates a boost out the door.

Yes its 120 gallon tank and have 80+ pounds of live rocks thats been it it for well over a year. As far as the canister, I tried everything, more filters, less filters, routine maintenance, etc, Nitrates never got under control. Sump is in and running great and I did a large water change this past weekend and doing 20% weekly. I realize it will take time to control, just wanted to confirm removing the Fx6 wouldn’t create any additional problems.

Thank you all for the info!