Nitrates, phosphates and alkalinity achieving balance in my reef

[MrGisonni]

My 30 mixed reef is two years old. I started with "life" rock and it seemed to take a year before I achieved real stability and progress. I perform water changes with NSW, skim, have some macro growing in my display, run a small amount of rowaphos and carbon in a tiny AIO uv sterilizer, and dose AFR. Have 3 fish, CUC and I am fairly packed with Ricordia, LPS and SPS. When I added my 3rd fish, a Sunburst Anthias I started feeding mysis. Phosphates run from .03 to .1 Nitrates now from my sweet spot of 20 to 35... to 40ppm. I do want to lower them a bit. The anthias is eating more flake now so less mysis.
So I added Brightwell cubes to a chamber in my sump and have seen no Nitrate lowering this last month. My Alkalinity has dropped from very stable between 8.1 and 8.7, to 7 and my Calcium is 465 on my Hanna. I have seen a big increase in coralline algae that may be responsible for this. I added a bit of TR Balling Part B. And I am planning to add some Brightwell Reef Biofuel bc I think I may be carbon limited. The question is...Is my plan solid???? Let phosphate rise a bit by decreasing my rowaphos amount and schedule, aid bio cubes by providing carbon, allow them to consume NO3 and increase Alkalinity while bolstering the AFR with a small amount of TM Balling Part B?!? How does the plan sound???

 

[MrGisonni]

My alk drop may be due to an increase in coralline algae. It has just started to take off. My calcium is 465 on my hanna

 

[Randy Holmes-Farley]

B. And I am planning to add some Brightwell Reef Biofuel bc I think I may be carbon limited. The question is...Is my plan solid????

ALL reef aquaria (as well as the ocean) are and should be organic carbon limited to bacteria growth. Brightwell's discussion on this matter is quite illogical and should be ignored, IMO.

That said, dosing organic carbon can be a fine plan when nutrients, especially nitrate, are on the high side. A positive side effect is the feeding of many filter feeders by the bacteria, and potential direct supply of organics to corals, sponges, etc.

 

[MrGisonni]

My little reef for reference.

 

[MrGisonni]

ALL reef aquaria (as well as the ocean) are and should be organic carbon limited to bacteria growth. Brightwell's discussion on this matter is quite illogical and should be ignored, IMO.

That said, dosing organic carbon can be a fine plan when nutrients, especially nitrate, are on the high side. A positive side effect is the feeding of many filter feeders by the bacteria, and potential direct supply of organics to corals, sponges, etc.

Is my alk drop with stable Calcium due to increasing nitrification and an increase in coralline algae growth??

 

[Randy Holmes-Farley]

Is my alk drop with stable Calcium due to increasing nitrification and an increase in coralline algae growth??

Coralline and corals use calcium, alk, and magnesium in a relatively fixed ratio. About 18-20 ppm calcium, 0-2 ppm magnesium and 2.8 dKh of alkalinity.

Rising or falling (or dosing) nitrate will impact alk and not calcium. Rising nitrate depletes alk, falling or dosing nitrate adds it. Steady nitrate without dosing it will not impact alk.

 

[MrGisonni]

@Randy Holmes-Farley I read an old comment of yours where you mentioned that coralline uses more alk than it does calcium. If that still true in your opinion?

 

[Randy Holmes-Farley]

@Randy Holmes-Farley I read an old comment of yours where you mentioned that coralline uses more alk than it does calcium. If that still true in your opinion?

I don’t believe that is what I intended to say. Coralline uses them in the ratio of 2.8 dKH, 2 ppm magnesium and about 18 ppm calcium.