No phosphates high nitrates

lennyd19 · Sep 21, 2018

So I have been keeping tanks for over 15 years generally no larger than 100 gallons. I put together a frag system about 260ish gallons in total. The system has been running for over a year and two months.

Frag tank 50 gallons
Fuge 40 breeder
170 gallon sump

I am have a really hard time to get the system balanced. Everything is in check except nitrates they are 40-50ppm nyos test kit.
I primarily keep sps in my main tank with no issues.
I can not keep one piece of sps in the frag setup. So I had a icp test done in the water. They said my only issue is the nitrates. They told me also with no phosphates I need to add some so I did. Within 48 hrs back to zero. They then said add a carbon source which I have not done yet. I do have a bio pellet reactor that has been on line for over 3 months and it has not even put a dent in the nitrates. So at this point here I need some help. I am at a total loss.

Potatohead · Sep 21, 2018

I was/am having the same problem, which is more of an issue of low phosphate than high nitrate. In order for your nitrate to fall, you need phosphate. Keep the biopellet reactor online and get some Brightwell Neophos, Seachem flourish phosphorous or something similar (I use a trisodium phosphate solution) to actually dose phosphate. You will then start to see nitrate come down and your corals will recover.

I did an ICP test and my nitrate was 53 while my phosphate was undetectable. I have since started dosing .06 ppm phosphate per day along with some nopox, in about a month my nitrate has come down to about 20-25 and phosphate hovers about .02. Corals are much happer.

lennyd19 · Sep 21, 2018

I am dosing the neo phos. Have only been dosing around a week. So I guess I will continue to monitor. I just never had a tank with no phosphates lol. Do you think it would benefit to skim for 12-18 hrs a day instead of 24 hrs?

Potatohead · Sep 21, 2018

I kept mine running all the time, with carbon dosing or biopellets I wouldn't turn it off. Dose more phopshate if you need to. It takes some time to start to stay in the water column because your rock will suck a lot of it up.

lennyd19 · Sep 21, 2018

Ok time to hook the doser up.

Potatohead · Sep 21, 2018

One more thing, I would keep the flow on your biopellet reactor onthe slow side to start, just enough to tumble. Reason being when you start to add more phosphate the bacteria in there will colonize and start to pull out nitrate rapidly. You don’t want that to happen too fast not only because changing nitrate too fast may be detrimental, but also because you won’t keep any phosphate in the water. Dose enough to keep some in the water. I dose .06 but my water only tests about .02. Eventually it will balance out.

Randy Holmes-Farley · Sep 22, 2018

I'd certainly dose phosphate before I reduced skimming time, but I might feed more too.

lennyd19 · Sep 28, 2018

So I have dosed phosphates and up the feeding a bit. I did check nitrates today still above 40ppm. Phosphates are taking a little longer to go down shows at .01 and I dosed 4 days ago.

lennyd19 · Dec 20, 2018

I am still in battle with this issue. Dosed phosphates for about a month and a half still had no success. Phosphates are still present now. The nitrates have not budge. Any suggestions would be great.

rock_lobster · Dec 20, 2018

lennyd19 said:
I am still in battle with this issue. Dosed phosphates for about a month and a half still had no success. Phosphates are still present now. The nitrates have not budge. Any suggestions would be great.

How much chaeto are you trashing per week?

lennyd19 · Dec 20, 2018

The growth has slowed down a bit. I was doing about a 5 gallon bucket every 2 weeks.

Super Fly · Dec 21, 2018

Have you tried increasing PO4 dosing?

Mine has 87 ttl water volume and had NO3 - 5 and PO4 - 0. So I started dosing 2ml/day Seachem Flourish Phosphorus while turning down skimmer from 24hrs to 12 hrs/day starting from 12/9, after a week it didn't raise PO4. Then I increased dosing on 12/16 to 3ml/day while completely turning off the skimmer and last night PO4 finally measured 0.05
This week I also increased nori feeding to every 2 days from once a week.

FYI - we discuss in this thread https://www.reef2reef.com/threads/undetectable-phosphates.352249/page-6#post-5492767

lennyd19 · Dec 21, 2018

I will take a look at the thread. Thank you for the info. I did increase po4 to desired level. But still had no change in nitrates after about 7-8 weeks.

Super Fly · Dec 21, 2018

have u tried doing lots of water changes to reduce NO3?

Big E · Dec 22, 2018

Take out the algae filter and just carbon dose............that's one less P04 stealer. Also a bacterial driven system is going to work much better without the algae filter.

I'd also take the biopellets out as well and only carbon dose. You'll find once you get control of your nutrient levels they'll be easier to control and adjust only carbon dosing with a skimmer.

If you do both this will get you back to a basic bacterial system. Without P04 dosing your levels will go up. Hold off carbon dosing till you see where things start to balance out or adjust. It will take 2-3 weeks.

What kind of fishload is in this tank? How much rock?

Randy Holmes-Farley · Dec 22, 2018

Boosting phosphate will only cause a reduction in nitrate if phosphate is the limiting factor for some organism to consume ammonia or nitrate. If anything else is limiting (light, space, trace elements such as iron or manganese, organic carbon for bacterial growth, etc) then nitrate will not decline.

lennyd19 · Dec 22, 2018

I have tried 30-60gal water changes. Did not budge. The fish load is scopis , yellow tang, six line and a algae blenny. There is around 225lbs of rock. I used BRS dry rock. But did cure for over a year.

lennyd19 · Dec 22, 2018

Randy Holmes-Farley said:
Boosting phosphate will only cause a reduction in nitrate if phosphate is the limiting factor for some organism to consume ammonia or nitrate. If anything else is limiting (light, space, trace elements such as iron or manganese, organic carbon for bacterial growth, etc) then nitrate will not decline.

You think I should continue to dose phosphates? I did this and there was no change but unwanted algae growth.

Big E · Dec 23, 2018

lennyd19 said:
I have tried 30-60gal water changes. Did not budge. The fish load is scopis , yellow tang, six line and a algae blenny. There is around 225lbs of rock. I used BRS dry rock. But did cure for over a year.

With that huge water volume (260g)that is a tiny fish load. Why is the sump so big?........... other than to hold all that rock, which is more than enough for a 1000g+ system. Since the frag tank is small I would eliminate the sump altogether You don't need 225lbs. of rock for a tank like that............you need maybe 10 lbs.

I would dump the algae filter and use the 40 breeder as your sump.....put some rock in there or if you want to use less space you can put a bag of Siporax or similar product with a small amount of rock.

You need to essentially get back to square one and reduce the water volume & cut back on your export system with just the skimmer......... make the system easier to deal with and control right now. Once you see where you're at you can move forward.

As an example my frag tank--

Total system volume- 60 gallons- tank is 60g Rimless but really only holds 50g
5-8lbs of rock, maybe less.
One bag of Siporax I just added in the last year as the corals started filling up the tank.
Sump is a ten gallon tub that holds the rock and a skimmer.

Fish load-
Dejardinii tang- 4"
Cooks Island Canary Damsel- 2.5"
Nigripes clown pair- 3" & 2.5