Should I add phosphate to help lower my nitrates?
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AbsoluteZer0273
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Been really busy with the holiday fun. I finally tested my tank again today. The po4 is down to .08, and the no3 is around 50! Seems this is working! I did a 50 gallon water change again on Sunday. I’m going to add more phosphate tonight, and see if I can finally get these nitrates under control.
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Did another 50 gallon water change. This seems to be working. My nitrates are down to 40-50 ppm and the phosphate has been reduced from over 1ppm to 0.14 ppm in about 2 weeks.
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Sorry for the delay! It’s been a crazy week! I checked the NO3 and PO4 a couple days ago and the nitrates look to be down to 40 ppm and phosphates are down to 0.04! I need to do a water change this weekend and possibly add see where everything it at after that. I have also been working on a Donavan nitrate destroyer. I’m going to try and get it online this weekend also. This should solve all my nitrate problems!
https://www.reef2reef.com/threads/poor-man-nutrients-control-donovans-nitrate-destroyer.302685/
Chiming in a bit late on this thread but it's really an interesting one -- I just read through it. I'm a bit surprised this is working so well but since it is, I'd keep at it but with some cautions. I think that with your nitrates having sat this high for a while, you have a vast supply of nitrate locked up on the sand bed and rock. By dosing phosphate, you're building sufficient bacterial colonies in your pellet reactor and throughout the tank to consume the nitrates but, as you get them down, more will leach out from the rock and sand. Don't be surprised if you find a floor that you struggle to get nitrates below -- and I suspect that floor will be well above levels that are sustainable long term for a reef. If you get there, I'd resist the urge to just keep dumping in more phosphate for fear that you're just pushing up the nutrient load. Keep in mind that the nutrients being bound up in the reactor mulm may be getting skimmed out, but there are many nutrients being tied up in colonies throughout all surfaces of your tank, rock and sand that are not. Adding phosphates may help those colonies lock up more nitrates and keep them away from your test kits but they're still in the tank ready to be released into the water column.
So, if this were my tank, I'd try to remove a lot of what you have added -- both chemically and forms of substrates for nutrients, including any plates, sponges or other porous materials. Keep doing water changes. If you have the capacity and budget, I'd consider setting up a second tank or vat to cure some quality live rock and, once you get your nitrates as low as you can without adding much more phosphate, start subbing some good live rock in for what you have. There's nothing wrong with starting with dry rock but, by now, your rock is saturated with nutrients and will continue to leach them into the water whenever the level in the water is lower than the level in the rock. Same with your sand, but that's easy to swap out.
As for your water changes, I assume you're using RO/DI water but would suggest you run tests on your mixed up replacement saltwater to make sure you're not inadvertently adding nitrates.
Lastly, for sustainable carbon dosing that, in my experience, keeps nitrate and phosphate low and balanced, consider switching from biopellets to vinegar dosing. I was a big fan of biopellets when they first hit the scene but the longer I used them the more I struggled not only with nitrate/phosphate balance but also with Cyano outbreaks. I switched to vinegar and couldn't be happier. But be forewarned, it's not an overnight fix. You really need to gradually ramp up vinegar dosing, hone it in to your tank's needs (which in your case are still changing rapidly) and then be patient. It's also ok to run pellets and vinegar together while transitioning. What worked for me is to remove half the pellets and start a small vinegar dose (10ml/day on my 300g system) and then gradually increase vinegar and just let the pellets dissolve over time. Haven't seen a speck of cyano since and only need to clean the tank glass about 2x a month now.
Lastly, the Hanna meter you got is a great step up from the API meter but it's still a high range -- parts per million. I suggest getting the ultra low range meter, which measures in parts per billion. I find that my tank does best when phosphates are between 20 and 50 ppb, which is too low to accurately read on a ppm meter. For comparison, when your phosphates hit 1.14 ppm, that was 1140 ppb - about 50 times where I'm finding the best results. While you're using your PPM meter, I would consider any phosphate that registers on it above 0.0 to be enough and anything above 0.03 too much. Due to the inaccuracy of trying to gauge millimeters with a car odometer, you might consider anything above 0 to be too much.
Good luck and please keep us updated. This really is an interesting experiment.
So, if this were my tank, I'd try to remove a lot of what you have added -- both chemically and forms of substrates for nutrients, including any plates, sponges or other porous materials. Keep doing water changes. If you have the capacity and budget, I'd consider setting up a second tank or vat to cure some quality live rock and, once you get your nitrates as low as you can without adding much more phosphate, start subbing some good live rock in for what you have. There's nothing wrong with starting with dry rock but, by now, your rock is saturated with nutrients and will continue to leach them into the water whenever the level in the water is lower than the level in the rock. Same with your sand, but that's easy to swap out.
As for your water changes, I assume you're using RO/DI water but would suggest you run tests on your mixed up replacement saltwater to make sure you're not inadvertently adding nitrates.
Lastly, for sustainable carbon dosing that, in my experience, keeps nitrate and phosphate low and balanced, consider switching from biopellets to vinegar dosing. I was a big fan of biopellets when they first hit the scene but the longer I used them the more I struggled not only with nitrate/phosphate balance but also with Cyano outbreaks. I switched to vinegar and couldn't be happier. But be forewarned, it's not an overnight fix. You really need to gradually ramp up vinegar dosing, hone it in to your tank's needs (which in your case are still changing rapidly) and then be patient. It's also ok to run pellets and vinegar together while transitioning. What worked for me is to remove half the pellets and start a small vinegar dose (10ml/day on my 300g system) and then gradually increase vinegar and just let the pellets dissolve over time. Haven't seen a speck of cyano since and only need to clean the tank glass about 2x a month now.
Lastly, the Hanna meter you got is a great step up from the API meter but it's still a high range -- parts per million. I suggest getting the ultra low range meter, which measures in parts per billion. I find that my tank does best when phosphates are between 20 and 50 ppb, which is too low to accurately read on a ppm meter. For comparison, when your phosphates hit 1.14 ppm, that was 1140 ppb - about 50 times where I'm finding the best results. While you're using your PPM meter, I would consider any phosphate that registers on it above 0.0 to be enough and anything above 0.03 too much. Due to the inaccuracy of trying to gauge millimeters with a car odometer, you might consider anything above 0 to be too much.
Good luck and please keep us updated. This really is an interesting experiment.
Chiming in a bit late on this thread but it's really an interesting one -- I just read through it. I'm a bit surprised this is working so well but since it is, I'd keep at it but with some cautions. I think that with your nitrates having sat this high for a while, you have a vast supply of nitrate locked up on the sand bed and rock. By dosing phosphate, you're building sufficient bacterial colonies in your pellet reactor and throughout the tank to consume the nitrates but, as you get them down, more will leach out from the rock and sand. Don't be surprised if you find a floor that you struggle to get nitrates below -- and I suspect that floor will be well above levels that are sustainable long term for a reef. If you get there, I'd resist the urge to just keep dumping in more phosphate for fear that you're just pushing up the nutrient load. Keep in mind that the nutrients being bound up in the reactor mulm may be getting skimmed out, but there are many nutrients being tied up in colonies throughout all surfaces of your tank, rock and sand that are not. Adding phosphates may help those colonies lock up more nitrates and keep them away from your test kits but they're still in the tank ready to be released into the water column.
So, if this were my tank, I'd try to remove a lot of what you have added -- both chemically and forms of substrates for nutrients, including any plates, sponges or other porous materials. Keep doing water changes. If you have the capacity and budget, I'd consider setting up a second tank or vat to cure some quality live rock and, once you get your nitrates as low as you can without adding much more phosphate, start subbing some good live rock in for what you have. There's nothing wrong with starting with dry rock but, by now, your rock is saturated with nutrients and will continue to leach them into the water whenever the level in the water is lower than the level in the rock. Same with your sand, but that's easy to swap out.
As for your water changes, I assume you're using RO/DI water but would suggest you run tests on your mixed up replacement saltwater to make sure you're not inadvertently adding nitrates.
Lastly, for sustainable carbon dosing that, in my experience, keeps nitrate and phosphate low and balanced, consider switching from biopellets to vinegar dosing. I was a big fan of biopellets when they first hit the scene but the longer I used them the more I struggled not only with nitrate/phosphate balance but also with Cyano outbreaks. I switched to vinegar and couldn't be happier. But be forewarned, it's not an overnight fix. You really need to gradually ramp up vinegar dosing, hone it in to your tank's needs (which in your case are still changing rapidly) and then be patient. It's also ok to run pellets and vinegar together while transitioning. What worked for me is to remove half the pellets and start a small vinegar dose (10ml/day on my 300g system) and then gradually increase vinegar and just let the pellets dissolve over time. Haven't seen a speck of cyano since and only need to clean the tank glass about 2x a month now.
Lastly, the Hanna meter you got is a great step up from the API meter but it's still a high range -- parts per million. I suggest getting the ultra low range meter, which measures in parts per billion. I find that my tank does best when phosphates are between 20 and 50 ppb, which is too low to accurately read on a ppm meter. For comparison, when your phosphates hit 1.14 ppm, that was 1140 ppb - about 50 times where I'm finding the best results. While you're using your PPM meter, I would consider any phosphate that registers on it above 0.0 to be enough and anything above 0.03 too much. Due to the inaccuracy of trying to gauge millimeters with a car odometer, you might consider anything above 0 to be too much.
Good luck and please keep us updated. This really is an interesting experiment.
So, if this were my tank, I'd try to remove a lot of what you have added -- both chemically and forms of substrates for nutrients, including any plates, sponges or other porous materials. Keep doing water changes. If you have the capacity and budget, I'd consider setting up a second tank or vat to cure some quality live rock and, once you get your nitrates as low as you can without adding much more phosphate, start subbing some good live rock in for what you have. There's nothing wrong with starting with dry rock but, by now, your rock is saturated with nutrients and will continue to leach them into the water whenever the level in the water is lower than the level in the rock. Same with your sand, but that's easy to swap out.
As for your water changes, I assume you're using RO/DI water but would suggest you run tests on your mixed up replacement saltwater to make sure you're not inadvertently adding nitrates.
Lastly, for sustainable carbon dosing that, in my experience, keeps nitrate and phosphate low and balanced, consider switching from biopellets to vinegar dosing. I was a big fan of biopellets when they first hit the scene but the longer I used them the more I struggled not only with nitrate/phosphate balance but also with Cyano outbreaks. I switched to vinegar and couldn't be happier. But be forewarned, it's not an overnight fix. You really need to gradually ramp up vinegar dosing, hone it in to your tank's needs (which in your case are still changing rapidly) and then be patient. It's also ok to run pellets and vinegar together while transitioning. What worked for me is to remove half the pellets and start a small vinegar dose (10ml/day on my 300g system) and then gradually increase vinegar and just let the pellets dissolve over time. Haven't seen a speck of cyano since and only need to clean the tank glass about 2x a month now.
Lastly, the Hanna meter you got is a great step up from the API meter but it's still a high range -- parts per million. I suggest getting the ultra low range meter, which measures in parts per billion. I find that my tank does best when phosphates are between 20 and 50 ppb, which is too low to accurately read on a ppm meter. For comparison, when your phosphates hit 1.14 ppm, that was 1140 ppb - about 50 times where I'm finding the best results. While you're using your PPM meter, I would consider any phosphate that registers on it above 0.0 to be enough and anything above 0.03 too much. Due to the inaccuracy of trying to gauge millimeters with a car odometer, you might consider anything above 0 to be too much.
Good luck and please keep us updated. This really is an interesting experiment.
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FWIW, nitrate does not bind to rock and sand surfaces the way that phosphate does.
DrSamwise
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Super interesting thread. Any update on progress?
I do have exactly the same problem with phosphate 0.00 mg/l based on Hanna and NO3 4-5 mg/l. Trying to get NO3 down to <1 mg/l to approach ULNS, but really hard to get it down. Feeding quite heavily with frozen and pellet food, but haven't dosed phosphate directly. Though I do have small amount of phosphate binding material + zeolite in media reactor, I´ve been hesitant to remove it all as not to shock the system too much, but I have been reducing the flow to the reactor from 450 l/h => 300 l/h and going to drop still a bit more.
I do have exactly the same problem with phosphate 0.00 mg/l based on Hanna and NO3 4-5 mg/l. Trying to get NO3 down to <1 mg/l to approach ULNS, but really hard to get it down. Feeding quite heavily with frozen and pellet food, but haven't dosed phosphate directly. Though I do have small amount of phosphate binding material + zeolite in media reactor, I´ve been hesitant to remove it all as not to shock the system too much, but I have been reducing the flow to the reactor from 450 l/h => 300 l/h and going to drop still a bit more.
I would get a salifert or like kit if your going to get nitrate to sea water levels. Api reads nitrate really bad at lower numbers.
DrSamwise
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I have Tropic Marin Pro NO3 test (previously used Salifert). It does have better resolution on lower end than Salifert, though Salifert is not bad either. We really don't have API tests much here in Finland, actually never seen one in LFS or in use.
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