Nitrate problems

aquablizz · Jul 19, 2016

I have a fish only 75 gal display tank with average fish load maybe a total of 14inchs total fish length. Include in the tank is a crushed coral substrate along with some live rock and large dead coral pieces for decoration..

I also have a 40 gal sump (30 gal of water) with a refugee um and a AquaC EV180 skimmer.

The fish all seem to be doing well but I can not get my nitrates down to save my life.

I have zero ammonia, zero nitrites and zero phosphates but my nitrates are at 100ppm.

I also notice that my skimmer does not pull much skim out and my macro algae is staying at about the same size.
I only feed once a day and give the fish what can be eaten in 2 minutes and that is with the filter running.
Do you have any thoughts of what my problem might be?? Also I do water changes about once a month and have a topoff system using RODI that I make in house..
I also run my return through a sterilizer light.

Any thoughts would be appreciated..
Thanks in advance
Gary Blizzard

twilliard · Jul 19, 2016

Hi Gary
At this point I would consider a large water change (75%)
It's hard to explain the end process of carbon and organics to no3

Animagus · Jul 19, 2016

Your Nitrates are high because your tank is struggling to process all the crap within it. Remove this and you'll lower that. It's actually pretty simple. If your not doing so already you might want to get into the habit of vacuuming that CC substrate on a regular basis. This, in combination with not overstocking, not overfeeding etc and you should see your Ntrates start to fall over time. GL.

aquablizz · Jul 19, 2016

I do vacuum the substrate and do not have a heavy load of fish for over 100 gal of water.. also as I previously stated I only feed once a day what can be consumed in 2 minutes and that is with the filters running..

I'm stumped.... I always vacuum when I do a water change so I'm sort of at a loss as to what is creating the problem..

Thinking of doing away with the crushed coral substrate and going with a medium grain sand.

Thanks for the input

Blizz

mrvn · Jul 19, 2016

Have you considered carbon dosing?

jsker · Jul 19, 2016

Gary, how old is the system? I ran several fish only systems before getting the full blown reef bug. On those systems I run the Berlin system of filtration, using the live rock and the filter after about 6 months I would pull the bio media. I now run bio pellets in my system to bring down my ski high nitrates. The pellets have brought down the nitrate by 40 ppm in the last month, but I do not want the nitrates completely gone for the corals. Water changes are great but only temporary. There are member dosing different type of carbon such as vodka, vinegar. I might suggest reading up on vinegar dosing, it is the least expensive of the dosing methods.

Randy Holmes-Farley · Jul 19, 2016

There are many good ways to reduce nitrate.

I detail them here:

Nitrate in the Reef Aquarium - REEFEDITION
https://www.reef2reef.com/blog/nitrate-in-the-reef-aquarium

aquablizz · Jul 20, 2016

Thanks again for all the replies..
My display tank is 25 years old.. This past April I put in a 40 gal sump with the intent to possibly get into invert and corals.. The fish all appear to be healthy but I do have to battle brown algae on a regular basis. I went with a much better skimmer and put in a reactor with bio pellets but I've been struggling with keeping the pellets suspended as they tend to load up and sit on the bottom of the reactor within a week and I get no movement at all. My refuge compartment has about 25# of live rock along with some Cheato.. As I stated earlier,, the cheato does not appear to be growing, pretty much the same size as when I put it all together. I run my light 12 hrs. per day in the sump on a timer. I thought the skimmer was dialed in correctly but I'm not getting much skim at all compared to when I first put it in service.
I guess I should start dosing but was hoping to get to the root of the problem first.

Thanks again for all the suggestions
Blizz