Will algae removal raise NO3 and reduce PO4?

[scubaboy]

I have had the issue with 0 Nitrates and high PO4, which range from .2 to .6 for years. I have been fighting GHA for a very long time. Tank is 2.5 years old. I dont mind the higher PO4, not trying to get down to minimal readings, just balanced as I am trying to rid myself of the GHA. Chaeto in my sump and running a skimmer. I tried the LFS recommended "feed more" solution, but that is what drove my PO4 up over .6 with no increase of NO3, just increase in GHA.
My coralline is trying to come in, but I understand the higher phosphates may be limiting it's growth.

Please tell me if my new plan of attack makes sense;

Hitting this routine every day for a week
Hand removal of algae using syphon hose into sock
Scrubbing rocks to remove all the algae I can
15% WC every day / other day for the last week after I scrub rocks
cut way back on feeding, I only feed frozen PE Mysis and Reef Frenzy (about a total of the size of a single cube twice a day) Eight fish in total with lots of CUC, shrimp and various LPS and encrusting corals. All food gone in 2-3 minutes.

Total setup volume of 130 gal with DT and Sump

I want to fix this naturally and hoping if I get the GHA beat down, my NO3 will be readable.

Am I on the right track or do any of you have any additional suggestions?

Thanks for all your help in advance!

 

[jda]

Water changes are not great at lowering po4 since if you have .6 in the water column, then you have a massive, massive amount bound in the rocks and sand. You will likely need media if you want to lower this and it could take a lot of GFO or you can use Lanthanum Chloride. Both have their lovers and haters so read well and ask any questions.

Water changes are still a good idea for other reasons, but maybe 15% every few weeks is OK.

Removing the algae by mechanical means is a great idea. Chitons, limpets and urchins work great too, but you need numbers and not just one or two of them. Pencil and rock urchins from the Keys stay on there rocks more than other types, IME. You can help them out a lot by also manually removing.

The no3 is likely now because you have anoix bacteria converting no3 into N gas. This is no issue since the algae, along with the corals, can get all the nitrogen that they need from ammonia and nitrite.

Your no3 might never be above a trace, but that is of no consequence as long as you are feeding your fish well and have more available forms of nitrogen in the ammonia and nitrite. Even if you dosed nitrate, the anoxic bacteria would most likely multiply and use it all up anyway.

 

[scubaboy]

Water changes are not great at lowering po4 since if you have .6 in the water column, then you have a massive, massive amount bound in the rocks and sand. You will likely need media if you want to lower this and it could take a lot of GFO or you can use Lanthanum Chloride. Both have their lovers and haters so read well and ask any questions.

Water changes are still a good idea for other reasons, but maybe 15% every few weeks is OK.

Removing the algae by mechanical means is a great idea. Chitons, limpets and urchins work great too, but you need numbers and not just one or two of them. Pencil and rock urchins from the Keys stay on there rocks more than other types, IME. You can help them out a lot by also manually removing.

The no3 is likely now because you have anoix bacteria converting no3 into N gas. This is no issue since the algae, along with the corals, can get all the nitrogen that they need from ammonia and nitrite.

Your no3 might never be above a trace, but that is of no consequence as long as you are feeding your fish well and have more available forms of nitrogen in the ammonia and nitrite. Even if you dosed nitrate, the anoxic bacteria would most likely multiply and use it all up anyway.

Thank you for the reply, is having that level of anoix bacteria a good thing?

 

[jda]

It completes the nitrogen cycle by getting nitrogen out of the system. I love it. Once you understand that no3 is not a requirement to get nitrogen to anything in your tank, then it is easy not to worry about it.

 

[scubaboy]

So my understanding was if I could get the NO3 raised, it would in turn help to lower the PO4 which would help get rid of the GHA. Am I misunderstanding this?

 

[jda]

I don't think that it works like that. You can raise po4 to lower no3, but not the other way around.

There is another thread from today where some people indicated that raising nitrate would lower po4, but Dr. RHF chimed in that unless you are nitrogen deficient, then having more does nothing. With what you are feeding your fish, I doubt that you are nitrogen deficient at all.

I would not cut back on feeding. The fish waste is what feeds your corals. It feeds the algae too, but don't starve the fish and corals to try and get back at the algae - it won't work anyway. Just get more consumers.

 

[scubaboy]

Thank you so much @jda for your response and information.

Just so I am clear in my head;

Trying to balance my nutrients will not end my GHA issue, feed as usual and let it ride. My fish are fat and healthy so don't change anything
I need to do physical removal of GHA to get rid of as much as I can regularly
I need to increase my export some way, fine tuning my skimmer, increase lighting or something for my chaeto or some other means
Increase my CUC to help clean up rocks, add additional snails and urchins
Increase things that will help to uptake nutrients, like add more corals !!!!

Am I understanding you correctly?

 

[jda]

Go to ReefTopia or somewhere and order a 3-4 pack of pencil urchins and a 3-4 pack of rock urchins. They will help you out. It does not look like they are doing much for a while and then all of a sudden, the algae starts to disappear quickly. Keys are the best place to get these, IMO, but they might need a bit to recover from a Hurricane... but you get the idea.

Yes, keep removing algae by hand. You want the snails and urchins to clean down to the rock and not eat the ends and stuff.

If your only high parameter is po4, then you will likely need some media if you want to lower it. This could take a gallon or two of GFO using small amounts and changing daily.

Others don't feel this way, but for me, chaeto grows a LOT faster when po4 is lower. Your chaeto might take off as you lower po4 which can really help out.