fluval fx4

[nydobie]

would 2 fluval fx4's be enough filtration to run a tropheus/community tang tank for a 180g aquarium?

[frantic]

Will it work? Sure, but if it were me id do 2 fx6. It would give you 600 gph more movement and the extra tray for biomedia or whatever you chose to put in there. I have 2 on 125g.

[Mastiffman/ Duramax7Man7]

It's not only about the highest water flow. It;s about biological filtration as well. The water has to pass over the aerobic bacteria slow enough to remove the ammonia and nitrites to convert in into nitrates. If you have something like SeaChem Matrix that grows anaerobic bacteria deep inside, it will have to have water pass over it slow enough to also remove the nitrates.

I have found that turnover rate of water is not as important as we used to think. It's more about bio surface. An FX5/6 has about 35 sq feet of bio-surface which is more than enough to filter a 180g. It can easily filter a 400-500 tank with that much bio surface. Reason being is that the Beneficial Bacteria (BB) colony will only grow to the size of the bio-load (aka: food source). So if you have a bunch of fish in a stable tank and then remove half of the fish, the BB colony will die off to only half the size it was. If you then add more fish back to that tank after the die of BB has occurred, you will get an ammonia spike if you start feeding them right away and don't do proper water changes to compensate until the BB colony has reached the appropriate size to consume and convert the waste.

So as long as you have enough Bio-surface you are fine. And the FX5/6 has more than enough for a 180g. You would be better off taking the money for extra filtration and using it towards media and a good Jebao water circulation pump to lift waste off of the rocks and substrate and into the water column where it can get sucked into the filter and properly disposed of.

[rare]

Apr 16, 2018 12:23:29 GMT -5 Mastiffman/ Duramax7Man7 said:

If you have something like SeaChem Matrix that grows anaerobic bacteria deep inside, it will have to have water pass over it slow enough to also remove the nitrates.

Masti,

Have you tried and seen results? I really dont think I have came across anyone that says it does work. For others that wish to try this, dont buy seachem matrix. What they are using is pumice rocks/stone. Buy it online and get more and cost less.

[frantic]

I don't have any proof or tests done myself, but I've been using it for years without tank issues. I load up on it. I just stick with what works for me.

[rare]

I know it work as well. Im using pumice stone small... but im not using it as a denitrification.