Nitrate Levels Too High

[hardb0iled]

How big are your water changes?

Try 2 or 3 larger water changes (at least 40-50%), over a week. This should dilute the Nitrates down. Once the levels are below where you want them, use your test kit to monitor the water and determine how often you need to do your changes to keep the levels where you want them

Having high nitrates and no ammonia or nitrites means your filters are working well. Normal biological filtration produces nitrates - it doesnt get rid of them.

 

[scottchristian]

my water changes are always a minimum of 40% i guess ill try what hardboiled said and change the water a couple times a week and just keep checking it. maybe ill change it three days in a row and check it. i rotate cleaning the filters every few weeks.

 

[gasser]

I know in the salt hobby a deep sand bed consisting of very fine graned sand allows nitrate in a reef to remain 0 even after a year of no water changes. I was able to maintain my nitrates at 0 for almost 2.5 years feeding daily with no water changes. In the end, it was not the water that killed my coral but a faulty A/C unit that failed bringing the tank temp up to 100 degrees. In fact my SPS corals were a foot across so the tank was thriving with this system.
I know the bio load of these reef tanks is MUCH lower than the fresh tanks but I wonder if a refugium filled with very fine graned sand and some floating plants would greatly reduce the need for such frequent water changes.
I am working on changing my reef over to fresh and all the previous sumps and refugiums are still in place. I think I will set it up just like that and monitor my nitrates over time and see what happens. Should make an interesting experiment.

Jeff

 

[hardb0iled]

There are various ways to reduce nitrates besides water changes, basically you just need to house anaerobic bacteria which lives in the absence of dissolved O2. The problem is your fish need dissolved O2 to breath

There are various filter designs around which have varying degrees of success in housing the anaerobic bacteria and reducing nitrates, but most are either expensive to buy, complicated to build and maintain or they just dont work well. In the end for fresh water most people find it much simpler and easier to do regular water changes, which should be done anyway

Salt water on the other hand, doing weekly water changes can get very expensive, and be a major PITA! So they tend to perservere with denitrators - the deep sand bed filtration is one that is common - the bacteria live in the deep sand where there is little to no O2 in the water

 

[gomezladdams]

Verify your test kit is correct and check your water supply particularly if you live in a farming area