does live rock hold nitrates

[yacn]

Does anyone know if live rock hold nitrates? A LFS told me they don't.

My tank is 10+ years old and suffers from old tank syndrome....
I took out bio balls from sump, dismantled fuge area, the fuge area was only 16"x18"....I doubt enough area to really make a difference for my system, and added bio pellets 2 years ago.
I siphoned out all 6 inches of crushed coral over many months and got the last inch or so out of DT about 6 weeks ago. I also siphoned all crushed coral and sand out of my sump about 6 weeks ago.
I now have bare bottom 150 DT tank with 150 lbs of live rock in it, lots of mushrooms & zoas with 14 fish, and bare bottom 40 gallon sump with a skimmer & bio pellet reactor.

I bought a gyre 2 weeks ago to increase the flow in the DT....love it BTW.

I've done 3-4 water changes over the past 6- 7 weeks. 60 gallon water changes each time.
Blowing off live rock with a power head, and using filter socks only while doing this to catch the detritus. i siphon out as much detritus as I can from tank & sump.

I feel like this is the cleanest my tank has ever been!!

My nitrates drop for a day to 40-60 and then go up to 80 - 80+

I'm going to continue to do frequent water changes.....

I only have 2-32 gallon brute garbage cans to do water changes which are heated when I do.
I was thinking of doing one massive water change since I have a dozen 5 gallon buckets I can store salt water in but I don't have a way to heat all those buckets...this is in basement which is about 68 degrees. Tank is 78 Half the water would be heated and half wouldn't be.
Would that be okay to do?

Also curious if the live rock is holding nitrates and leaching them back into water after each water change.....cuz it sure seems like it. What else could be holding all these nitrates??

I have ATS on order but 2 month wait until I get it and then probably another month or two before it can begin making an impact....hoping this will help.

I was also thinking of buying a doser and begin dosing vodka or vinegar because bio pellets don't seem to help. I did have some success lowering nitrates about 2 1/2 years ago with vodka dosing but work travel made me switch to bio pellets.

[bertoni]

Live rock can't adsorb nitrate the way it can adsorb phosphate. If there is nitrate coming from the live rock, it's due to organic debris caught in or near it. The issue could be not enough live rock, although better skimming and reducing feeding might be appropriate.

Have you checked for nitrite? It's a rare problem, but nitrite will confuse nitrate test kits.

[Daddi0]

I dose vinegar through my ATO and it really helps with the nitrates.

[Dan_P]

Some Ideas

Assuming your test results are valid...

Nitrates are derived from the oxidation of ammonia. Ammonia, primarily a byproduct of biomass consumption, is increasing from a die-off in your aquarium.

If ammonia production is constant but nitrates are increasing, then the denitrification process has changed or is dying off in your aquarium. There is a claim that PO4 limited systems respond poorly to nitrate reduction through carbon dosing. Why wouldn’t this be a possibility when not carbon dosing?

I am not satisfied with the notion of accumulating nitrates or even organic material building up in an aquarium. Bacteria and fungus are everywhere, very hungry and very efficient digesters. Everything is food.

I don’t know what symptoms you have lumped under “old tank syndrome” but some of the changes to your system might have led to disruption of the bio filter and rise in nitrates.

[yacn]

Tested several times over last 6 to 7 weeks:
Ammonia - 0
Nitrites - 0
Nitrates - 80 to 80+ goes down after water change but goes back up within day or two
Phosphates - 1.0 was as high as 2.0
Mag - 1300
Cal - 440
Alk - 11
Salinity 1.023
Temp 78

I don't think I'm overfeeding. One to two algae sheets a week, and 3 to 4 frozen cubes twice a week.

I actually had cave ins of my live rock while doing these major water changes...forcing me to re-do the rock landscape. I shook and blew off the rocks while rebuilding. Between running gyre at 100% and using power head to blow off rocks & crevices before water changes I'm hoping I got most of the organic stuff caught in the rocks. There was a lot of it in the rocks. Hoping my efforts have reduced it significantly and will see positive results one day soon.

i'm seriously considering buying a doser and dosing vinegar soon. I was just hoping to lower the nitrates significantly first through water changes.....

[bertoni]

I would say that 3-4 cubes of frozen food probably is a massive amount of food for that size tank, but I don't know the size of the cubes that you are feeding. Spreading the feeding out might help some. A spike of nutrients might tend to accumulate as nitrate. Per day, I might feed one cube into the tank at most, based on the size of the old Formula 1 cubes.

[yacn]

Originally Posted by bertoni

I would say that 3-4 cubes of frozen food probably is a massive amount of food for that size tank, but I don't know the size of the cubes that you are feeding. Spreading the feeding out might help some. A spike of nutrients might tend to accumulate as nitrate. Per day, I might feed one cube into the tank at most, based on the size of the old Formula 1 cubes.

I'm feeding them 3 to 4 cubes twice a week. 6 to 8 total over a week's time period. That would average out to approx one cube per day.

Cube size are the frozen store bought cubes of mysis, brine, etc that most companies sell.

Then feed one 8x10 sheet approx of green algae twice a week...so 2 sheets a week.

For $35 bucks I'm going to buy another 32 gallon Brute garbage can so I can do larger water changes when needed. I have 3 heaters to heat all the water.

[bertoni]

I'd probably cut back to ½ cube per day and see how that goes, but there might be another issue. More live rock or a live rock substitute like the Marine Pure blocks might be needed.

[yacn]

Originally Posted by bertoni

I'd probably cut back to ½ cube per day and see how that goes, but there might be another issue. More live rock or a live rock substitute like the Marine Pure blocks might be needed.

I don't think I can fit much more rock in my DT. I've include an older pic (with crushed coral still in it instead of bare bottom today) to show you how packed I think my tank is with live rock.

I can add another larger marine pure block in my sump. I originally wanted to do that but Marine Pure customer service recommended I just start off with just one large block.

1/2 a cube of frozen food seems like not enough food. I feel bad only feeding them twice a week with frozen food .... but I'll cut back and see if that helps

I'm going to continue to do water changes weekly, bi-weekly until I see the nitrates go down. Not giving up....LOL Sooner or later its got to come down.....I HOPE

[yacn]

BTW .... thank's to all for posting and taking the time to offer advise... I really appreciate it!

[Dan_P]

Originally Posted by bertoni

I would say that 3-4 cubes of frozen food probably is a massive amount of food for that size tank, but I don't know the size of the cubes that you are feeding. Spreading the feeding out might help some. A spike of nutrients might tend to accumulate as nitrate. Per day, I might feed one cube into the tank at most, based on the size of the old Formula 1 cubes.

I agree that the number of cubes is sufficent to produce your nitrate levels but might the issue be insufficient nitrate removal via denitrification. Has the old system just lost its denitrification capability rather than you are feeding too much? Might the attempt to “fix” old tank syndrome instead killed the denitrification biofilter?

I plead my case so you don’t starve your fish but rather focus on nitrate export approaches.

[MrHyde]

Sort of off topic, but does rock hold/produce Hydrogen Sulfide? You know, that black stuff that sometimes appears beneath the sand.

[bertoni]

Some voids in the live rock might have some anaerobic decay happening, and that'd produce a bit of hydrogen sulfide. Unless there's a large amount of debris, that won't be a problem.