I have a 29 gal BioCube reef tank that has been established for 2 years. About 3 months ago, after some neglect on my part with infrequent water changes, I noticed some red slime algae. I got some stuff from my LFS "slimeanator", it wasn't the yellow powder, it was a light blue liquid that I added every 2 days for 2 weeks. It didn't seem to do anything. Meanwhile I was scrubbing and vacuuming the rocks, and doing water changes. During the treatment it said to remove all filters, so I did. I was running a refuge with macroalgae, and the media basket with chemipure and purigen. After 3 weeks or so I still have the red slime. So I asked the guy at my LFS, and he tells me to put a little hydrogen peroxide in the tank, and it will clear the algae right up. I added 1ml/10gal of 3% hydrogen peroxide into my tank, and it cleared the algae right up with in a few days. I put all my filter media back in, my tank looks great, my corals seem happy..... all is good I think.... Then I notice my hawk fish has popeye, so I quarantine him, and start to treat with antibiotics. I go back to the LFS and take a water sample, phos and calcium a little high, SG 1.022 (which I have since corrected - and now is 1.025), Ammonia 0, Nitrite 0, but my Nitrate is 160. I have since done water changes, every other day for the past week, and have hardly fed my fish anything. The nitrates will come down to about 40 then the next day shoot right back to 160. Any ideas as to why?
Why can't I get my nitrates down?
- Thread starter AmberRN
- Start date
- Tagged users None
Bouncingsoul39
Valuable Member
Maybe your rock or sand are leaching Nitrate. When you were cleaning the tank did you vacuum the sand bed? How large of wc are you doing? I'd do 4 25% water changes over a period of a couple weeks. Definitely give the sand bed a thorough vacuum if you haven't done that. What test kit is being used? Nitrate test kits are notorious for being really inaccurate so that's something to consider. Red Sea and Nyos are closest, but even they are off from the real number. API and Salifert are almost totally useless for nitrate. Dip strips are 100% useless for it.
atx100r
Active Member
Ihad an issue with the red slime. I did some reading and found it is different that normal algae. I cut all my lights excpet for blue for several weeks. I cleaned my tank really well. adn now it is gone. Ihave recently added DIY algae scrubber and carbon reactor that seem to have also helped quite a bit. I now have algae growing in my sump on the scrubber instead of the tank. I will say it is pesky stuf and if you cut those light on to soon it will start coming back over night.
Randy Holmes-Farley
Reef Chemist
Staff member
Super Moderator
Excellence Award
Expert Contributor
Article Contributor
R2R Research
My Tank Thread
- Joined
- Sep 5, 2014
- Messages
- 67,347
- Reaction score
- 63,689
Calcium carbonate binds phosphate, but not nitrate.
Randy Holmes-Farley
Reef Chemist
Staff member
Super Moderator
Excellence Award
Expert Contributor
Article Contributor
R2R Research
My Tank Thread
- Joined
- Sep 5, 2014
- Messages
- 67,347
- Reaction score
- 63,689
Killing lots of algae will cause a nitrate boost as the dead algae breaks down, but I do not think nitrate is really rising 120 ppm in a day. I expect there are testing protocol issues of some sort.
In any case, I'd look for some long term solutions to maintain nitrate.
I discuss them here:
Nitrate in the Reef Aquarium - REEFEDITION
https://www.reef2reef.com/blog/nitrate-in-the-reef-aquarium
Bouncingsoul39
Valuable Member
Thanks. It is possible though that a sand bed loaded with detritus would create Nitrate, right?
Randy Holmes-Farley
Reef Chemist
Staff member
Super Moderator
Excellence Award
Expert Contributor
Article Contributor
R2R Research
My Tank Thread
- Joined
- Sep 5, 2014
- Messages
- 67,347
- Reaction score
- 63,689
I did vacuum the sand bed. API test kit is what I was using. I have a local guy that just opened a really awesome new store that specializes in coral and such. He also tested my water with a different kind of kit (red reef or something) and said they were really high. I will keep doing water changes and see if I can get them down. I have done four 25% water changes in the last 2 weeks. If the algae was dying off would it continue to leach nitrate after this many weeks?? I am wondering if my fish getting popeye had anything to do with all of this ??
Thanks for the info..after the red slime cleared up I lost most of my cleanup crew, including a coral banded shrimp I had since I got my tank . I was afraid to get anything else with the levels so high, but could that help with the nitrates? Or add to them? I also had a sand sifting starfish that I haven’t seen and I suspect is also dead. I sifted through the sand with my fingers but can’t cant any remnants of her. Sorry for the stupid questions. I’m at a loss here.. my tank seemed to be in better shape when I was neglecting it!! My corals, however, look better than ever - and appear to love high nitrate levels - especially my mushrooms!!
Randy Holmes-Farley
Reef Chemist
Staff member
Super Moderator
Excellence Award
Expert Contributor
Article Contributor
R2R Research
My Tank Thread
- Joined
- Sep 5, 2014
- Messages
- 67,347
- Reaction score
- 63,689
Clean up crews and shrimp will not help reduce nitrate. They may slightly add to the levels as they consume algae and it gets metabolized.
Brew12
Electrical Gru
I would suggest getting a non-API nitrate test to use. I am in a similar situation to yours where my nitrates fluctuate way more than I think they should. Using my API nitrate test I thought my nitrates were jumping from oppm to 60+ppm overnight. I ended up getting a RedSea test kit to confirm. While my nitrates still fluctuate, it isn't by nearly as much as I first thought.
We talk about false positive tests for nitrites on a regular basis. Most nitrate test kits (probably all of them) break down the nitrate into nitrite and then read it. I don't know enough to understand exactly why but I think I have something fluctuating in my tank that causes my API test kit to read high that doesn't impact my Redsea kit nearly as much.
We talk about false positive tests for nitrites on a regular basis. Most nitrate test kits (probably all of them) break down the nitrate into nitrite and then read it. I don't know enough to understand exactly why but I think I have something fluctuating in my tank that causes my API test kit to read high that doesn't impact my Redsea kit nearly as much.
schooncw
Well-Known Member
Salifert useless for nitrate? I disagree!
Brew12
Electrical Gru
I agree. I don't even call my API test for nitrates useless. Its just a matter of figuring out how to use them and what they are telling us.
Lets face it, none of the test kits we commonly used are lab quality.
Stigigemla
Well-Known Member
It is important to realize what the nitrate tests do. They give you a very course estimation of the nitrate content in the water. You have a color chart to compare with your test and it has colored patches you use to compare to get the values. If it would be possible to get more accuracy the manufacturer of the test would have done more color patches. Its the price of having a test with such a great range.
You can get about 5 or about 10 as a value but if you imagine you have 6 - its just an imagination. The tests is not made for that.
If you kill cyano in your tank the poisons they have will be released in the water. So if you have a lot of cyano it will kill some animals.
I would make more waterchanges. To get a nitrate value of ten from 160 you theoretically need 10 25% waterchanges.
You can get about 5 or about 10 as a value but if you imagine you have 6 - its just an imagination. The tests is not made for that.
If you kill cyano in your tank the poisons they have will be released in the water. So if you have a lot of cyano it will kill some animals.
I would make more waterchanges. To get a nitrate value of ten from 160 you theoretically need 10 25% waterchanges.
Similar threads
