300 gallon filtration help

[jsodwi]

OK here is the set up presently. 300 gallon with a 38g sump mag drive 18. and 2 overflow boxes that will flow1800gph. And FX5 pretty much just loaded with bio balls and and 2 foam pads. The sump has about 8 gal of bioballs in it. I don't think the filtration is cutting it anymore. I have 11 big fish my levels have been fluctuating too much now especiallay nitrates, moving up to 40-60ppm I went from doing water changes every 7-10 days to every 3 days I cut feeding down to every 3 days now as well. The way my stand is designed I cant really get a bigger sump under the tank. I was going to get crazy and try to put a 55-75g sump in the basement and pump up with a massive pump. It is going to cost a lot and the time will be a lot to construct this. Would adding a second fx5 help me or should I really consider revamping the whole filtration

 

[Wheat]

How about a fluid bed filter? They're easy to build and take up less space. They can handle large bioloads for their size.

Here's a good DIY link for one: http://www.cichlid-forum.com/articles/diy_fbf.php

Don't think it'll solve your nitrate problem though. I have a high nitrate problem in my FW system and to cut down on water changes, I'm going to build one of the algae scrubbers here in the DIY section. They're supposed to take nitates down to 0 I think.

 

[cchhcc]

All you should be alarmed about is ammonia and nitrite. No filter is going to help you with your nitrates. You must change water to remove nitrates. We do not have denitrification in FW filtration. If you have no ammonia or nitrite your filter is sufficient.

With 11 big fish, you are ALWAYS going to have a nitrate problem to tackle. Nitrate is the end product of the FW nitrogen cycle, and 11 biggies will simply produce a lot of waste regardless of your feeding (respiration produces waste too).

There are denitrators, but work (if at all) only in low bioload situations and are not worth the money even then. Just change water.