After all that work, My Nitrates went back to 40ppms

[AMANIQU77]

My Trates used 2 b 160ppms. I did a 3-week aggressive clean up. I cleaned up all my filtration, skimmer, rocks, I removed all of them and syphoned the bottom, and I did enormouse amounts of pwc.

The pwc was this: 20G pwc once every 3 days, then 10G every other day, then 10G every week.

My nitrates went down to 10 ppms. I donated my trigger back to the LFS and now I did a pwc again after a week and a half. I got a reading of 40 ppms. Wow, all that work.....what happened?

Setup: 55G 4-ft tank with two (2) HOB Powerfilter 60, a Prizm Skimmer, a 400GPH PH with in tank quickfilter attachment, a 175GPH PH with wave maker attachment, and an Orbit 4x65 PC with Moonlight. I have 60 lbs of lr, 3 inches of ls (and a thin layer of cc beneath all that).

I have a maroon clown (2 inches) and a Blue Hippo Tang (2.5 inches). I also have one dozen small hermit crabs.

I don't see myself pwc-ing 10G per week. It's just tiring. I see myself changing 5G per week, but not 10. And I am a very patient person. however, I don't think my efforts are going anywhere. It's a waste! I don't have space for a HOB CPR fuge, and I have a coffee table tested for 900 lbs from Ikea. I don't have space beneath for anything.

Is there anyone who can help me?

Ammonia 0, Nitrite 0, Calcium 300 - 320, pH 8.3, temp 79F - 82F, Nitrates 40 ppms. Filtered tap (Carico 7-stage countertop filtration) reads zero Nitrates. I have green hair algae all over my rocks still. I don't think they are going away as long as there is food (nitrates). I use InstantOcean salt.

[DragonForce]

You should get some critters to work your sand bed. I think 55 nassarius snails would do nice. Try feeding 3x a week, this helped me quite a bit as well.

[melosu58]

Try checking your PWC water for phosphates. This could be a contributor to your algea. As far as tha nitrates cut back on your feedings.

[oyf709]

no if u keep doing 5g water change it will get u no where. If u want a quick solution to drop ur nitrate will be doing 50% water change every 3-4 days in 2 weeks ur nitrate should go back to normal, BUT!!!!! It just fix ur currrent problem not the root of the problem. U need to find out watz causing that nitrate spike soone ror later or u will face this all over again.
Btw, the more clean up u do to the sandbed the more possible u might break the sandbed and realeased ur nitrate. If u just syphoned the top layer without disturbing the deeper part of the sandbed it should be ok,however, if after u syphoned the sand bed ur water getting cloudy, that means u broke down the sandbed system which build up over the cycling process. That means u will need to wait till it settle down and start rebuilding the whole system. Try read more into the sandbed system from WWM so u will at least know wat u might did wrong.

[Omega]

Try using someone elses test kit yours could be expired

[AMANIQU77]

I did recently do a deep syphon of the sand bed. That's probably an aspect that made it worse. Thanks. I did get some brown water out to the bucket. And I ask myself "Wait a minute, my water is crystal clear, but I got this brownish water from my tank. Wow, this came from my tank. All a long it was in there". I might have distrubed the deep sand....

In terms of the tester, that's another possibility. It's a year old tester from Aquarium Pharmaceuticals.

I ordered Rowa-Phos, Phosphate tester, and AZ-NO3 from marinedepot today. I am planning on doing this de-nitrate-ing using chemicals above.

Please do give me some feedbacks on those products in relation to phospate and nitrates. Thank you. And thanks for the responses above as well.

[accorddude]

I have found that checking trates can be trikey. On my home kit they always show up at 60ppm or higher. But when ever I take my water to the fish store they are at 0. So maybe try a different test kit.