High Nitrate Issues

[High Desert Reefer]

Hello Everyone, I recently purchased a used 190 gallon system (150 gal DT, 40 gal refuge). The previous owner neglected the tank for months and now I am dealing with a large Nitrate issue, previous owner had system running 3-4 years.
Current Parameters as of 7/8/2020:
Salinity-35 ppt
Ammonia- 0.0
Nitrite- .05
Nitrate - 75-100(tough to tell on Salifert kit)
Phosphate - .05
PH-8.3
Stocked with 12 fish, 7 that came with tank and 5 that I already owned.
Nutrient removal system - Three Filter Socks, Vertex Omega 180i Skimmer, Live Rock 80-100 lbs, Live Sand (80lbs, 80lbs old sand rinsed thoroughly) Chaeto Algae. I have had this tank running in my home going on 2 full weeks. Did a 60 gallon water change when I received two weeks ago (6/27/20), 90 gallon water change on (7/4/20), anticipate 90 gallon water change for (7/11/20). Ammonia when first received was .2, nitrite 30, nitrate over 100, phosphate .3. Added Fritz 9 after last water change 7/4/20. Considering rinsing LR by blasting with large pump and change water to remove any decaying mater outside of tank and reinstalling. Need some help on lowering the Nitrates, open to suggestions?

 

[Lasse]

The nitrite level of 0.05 ppm will interact with your nitrate readings with between 50 and 100 times according to the brand in use. but in your case with a nitrate reading of 75 - 100 ppm a contribution to the readings from nitrite (if really 0.05) it does not matter.

How do your chaeto going? I think that a large refugium with a good growth of chaeto will do the job further on. The only thing you must look for is that your phosphate do not decline more - it will act as a chaeto growth inhibitor if it goes under 0.03 IME. Macro algae takes up N in a ratio between 50 - 80 times to every P. It means that for each ppm PO4 around 32-52 ppm NO3 will be taken up (if NO3 is the only N source). Just have an eye on the PO4 level and let the refugium do its job. If the PO4 level drops - you can add phosphate or feed a little with reef roids. If you run a GFO for the moment - take it offline till you have the NO3 where you want it - let the chaeto do its job. IMO - there is no problem to have tha PO4 to be around 0.1 during this time (before you have the NO3 where you want it).

Sincerely Lasse

 

[High Desert Reefer]

The nitrite level of 0.05 ppm will interact with your nitrate readings with between 50 and 100 times according to the brand in use. but in your case with a nitrate reading of 75 - 100 ppm a contribution to the readings from nitrite (if really 0.05) it does not matter.

How do your chaeto going? I think that a large refugium with a good growth of chaeto will do the job further on. The only thing you must look for is that your phosphate do not decline more - it will act as a chaeto growth inhibitor if it goes under 0.03 IME. Macro algae takes up N in a ratio between 50 - 80 times to every P. It means that for each ppm PO4 around 32-52 ppm NO3 will be taken up (if NO3 is the only N source). Just have an eye on the PO4 level and let the refugium do its job. If the PO4 level drops - you can add phosphate or feed a little with reef roids. If you run a GFO for the moment - take it offline till you have the NO3 where you want it - let the chaeto do its job. IMO - there is no problem to have tha PO4 to be around 0.1 during this time (before you have the NO3 where you want it).

Sincerely Lasse

Thanks for your response and it totally makes sense! The chaeto has doubled in size and still continues to grow. I did use GFO when I initial seen the large numbers when first tested and because the Ammonia I went to the GFO and knocked down the Ammonia and PO3. I have removed it since and wished I would have monitored my parameters more so that my PO3 would have remained a bit higher for better growth of chaeto. I really don’t plan on using GFO unless PO3 gets out of control. I measured PO3 with Hanna UL PO3 instrument tester...

 

[High Desert Reefer]

Lasse, would you concur with another 90 gallon water change? Also a heavy rinse of the Live Rock, to remove any existing detritus or decaying matter from being left in the high nutrient water environment? I would wash with change water not potable and I would is a high volume pump that I have available...?

 

[jda]

If that tank is as neglected as you are saying, then those rocks are full of bound phosphate to buffer that value quite well - it should not move too much if you do not use any media or chemicals. I would not use any media or chemicals on the P.

The chaeto will grow better when you get the N down and become even more effective. Water changes are cheap and could really help with the N. Sulfur denitrator works well, but is more of a solution to chronic issues and will become unnecessary in cases of neglect.

 

[High Desert Reefer]

If that tank is as neglected as you are saying, then those rocks are full of bound phosphate to buffer that value quite well - it should not move too much if you do not use any media or chemicals. I would not use any media or chemicals on the P.

The chaeto will grow better when you get the N down and become even more effective. Water changes are cheap and could really help with the N. Sulfur denitrator works well, but is more of a solution to chronic issues and will become unnecessary in cases of neglect.

Thanks for the response, I will do the water change as planned but would like to know the name of the products that are Sulfur denitrators? I will continue to allow the Chaeto to do its job, my worry is that my PO3 will run out before my nitrates are brought down to a more reasonable level. Testing with the Hanna instrument is indicating a decrease in PO3 every two days or so...would also like to know if a sure fire food or supplement that will make PO3 available if it is needed for supplementation to drive down the NO3...?

 

[jda]

Before you do anything, understand the relationship that po4 has with aragonite. You likely have a MASSIVE amount bound in the rocks and sand that will get released when the water level goes down. This acts like a buffer in low situations (good) and a reservoir in high situations (bad). It is not likely that it will go down too much using natural methods like chaeto/macro or water changes. If you do not use any chemicals or media, then this should be more than OK.

Sulfur denitrators are easy to find - just google them. If you get one and use it to lower the no3, then you might not need it once the job is done. They are more for continuous duty in tanks where the no3 will not stay low.

Also, why will your tank not process no3? Does it not have sand? Is the rock so gunked up that the pores will not accept water into the anoxic regions?

 

[jda]

Reading back through your first post, it might be that your live sand will start to process no3 once the anoxic areas get established again. This can take some time, but in a few months, this should start to work. It only takes about 2 inches for the sand to chew up no3 and turn it into nitrogen gas. If you have less than 2 inches, then this might not work.

 

[nereefpat]

Any guess how much rock you have? That processes N too.

Unlike phosphate, nitrate isn't bound in rock or sand....so water changes to drop nitrates is a simple mathematic problem.

What are the fish, by the way? If the tank is full of Naso tangs, lionfish, and eels, you'll never get the nitrates down.

 

[Lasse]

If you see a decrease of the PO4 - something is consume it faster than the rocks transport it out. Just have an eye on it and do not let it go lower than 0.03 ppm in PO4. I would not either clean up the tank - its a part of your reserves and biological life and as @jda point out a way to have the natural denitrification to kick on. A WC will lower the PO4 too. As long as I see the chaeto grow - I would relay that it is doing its job. IME - your level of NO3 will not decrease the growth rate of your Chaeto. I would try to stay at a PO4 level around 0.05 - 0.08 as long as nitrate is high. But that´s me - chose a way of handle it - and stick to that.

If you want to get the PO4 up - there is product for that but IME a coral food named Reef Roids is an excellent way to rise your PO4 and feed your corals at the same time.

Sincerely Lasse

 

[High Desert Reefer]

That is the issue, I feel that the LR that came with the tank is not cycling correctly or has sufficient bacteria due to neglect. Considering how poorly maintained the rest of the tank was I am feeling like the rock is plugged with years of waste or other precipitate. Pores could be plugged, hence the reason for a good washing, which I do not think would hurt any bacteria...?

 

[High Desert Reefer]

Any guess how much rock you have? That processes N too.

Unlike phosphate, nitrate isn't bound in rock or sand....so water changes to drop nitrates is a simple mathematic problem.

What are the fish, by the way? If the tank is full of Naso tangs, lionfish, and eels, you'll never get the nitrates down.

 

[High Desert Reefer]

Around 100 lbs.
Fish:
3 clowns
1 Powder Blue Tang
1 Purple Tang
1 Mimic Tang
1 Bicolor Angel
1 Flame Angel
1 purple goby
1 blue damsel

 

[High Desert Reefer]

Reading back through your first post, it might be that your live sand will start to process no3 once the anoxic areas get established again. This can take some time, but in a few months, this should start to work. It only takes about 2 inches for the sand to chew up no3 and turn it into nitrogen gas. If you have less than 2 inches, then this might not work.

I don’t believe I have 2 inches of sand at best 1.5 inches

 

[nereefpat]

Around 100 lbs.
Fish:
3 clowns
1 Powder Blue Tang
1 Purple Tang
1 Mimic Tang
1 Bicolor Angel
1 Flame Angel
1 purple goby
1 blue damsel

A little light on rock, then, but not terrible.
The stock list is fine for that much water volume.

I bet with some time and water changes, you can get those numbers down to a reasonable level.

Personally, I wouldn't take the tank apart and wash the rocks. I would just keep doing water changes and tracking the numbers. If that doesn't work, you can do some more drastic measures like a remote deep sand bed or a sulfur denitrator. Good luck.

 

[High Desert Reefer]

A little light on rock, then, but not terrible.
The stock list is fine for that much water volume.

I bet with some time and water changes, you can get those numbers down to a reasonable level.

Personally, I wouldn't take the tank apart and wash the rocks. I would just keep doing water changes and tracking the numbers. If that doesn't work, you can do some more drastic measures like a remote deep sand bed or a sulfur denitrator. Good luck.

Thanks!

 

[Lasse]

As I said before - I would not continue with WC - I would just take it easy and watching the Chaeto grow. It is not any catastrophic figures you have. Your NO3 levels does not hurt the fishes.

If you chose the path of WC - keep a close eye on PO4.

How much and which type of corals do you have ?

Sincerely Lasse

 

[High Desert Reefer]

Don’t have much in corals right now probably a dozen maybe with half being frag size. Acan, Kenya Tree, several polyps, variety of mushrooms. Pulsing Xenia’s. Not much.

 

[High Desert Reefer]

Okay I will just do a weekly 10% since I have the water waiting next to the tank.

 

[High Desert Reefer]

As I said before - I would not continue with WC - I would just take it easy and watching the Chaeto grow. It is not any catastrophic figures you have. Your NO3 levels does not hurt the fishes.

If you chose the path of WC - keep a close eye on PO4.

How much and which type of corals do you have ?

Sincerely Lasse

Hello Lasse, update on the high nitrates, they finally came down to 2-5ppm hard to tell exactly where the number lies and the PO4 hangs around .07-.09 PPM. I have had red slime that was on the sand and rock that has been around since the start of the tank, I presumed due to high nutrients, however now that my numbers are low it still continues to come back on the rock. I do a weekly 10% WC and siphon off rock, looks great for two or three days but comes back. I did one treatment with chemclean which seemed to help but didn’t get rid of. I was planning to do another treatment but thought I would get some advice first...?