Optimal Alkalinity Relationship to Nutrients

[AllSignsPointToFish]

I have a mixed reef, and the LPS always seem to do pretty well. I have times where SPS seem to thrive and other times (like now) when things just don't seem right.

Is there an optimum alkalinity relationship to nitrate/phosphate levels? I see people making statements about alkalinity being too high/too low for certain nutrient levels, but I've not been able to find literature explaining how those qualitative assessments are made.

My alkalinity always runs 9.5-10.6 dKH. However, I'm starting to think that the high alkalinity is why my SPS suffer.

My phosphates run 0.04-0.08 ppm and my nitrates are typically 1-3 ppm.

I'd like to try lowering my alkalinity to see if that helps with SPS, but I'd first like to understand the relationship between alkalinity and nutrient levels.

 

[piranhaman00]

I dont know the optimal ratio but yours is off for sure. Too high alk for that low of nutrients.

 

[lroberts108]

I have the same question as OP, I would like to know what the correct ratio is. Are we saying that in order to run high ALK you should run high nutrients?

 

[AllSignsPointToFish]

As an update, the tank looks much happier at a dKH of around 8.1 instead of 10 with the same nutrient levels. FWIW.

 

[lroberts108]

Thanks for the update!! I will also be lowering my alk. Do you use nopox?

 

[AllSignsPointToFish]

Thanks for the update!! I will also be lowering my alk. Do you use nopox?

I used to use it. I just use straight vodka now.

 

[Randy Holmes-Farley Verified Community Expert]

I have the same question as OP, I would like to know what the correct ratio is. Are we saying that in order to run high ALK you should run high nutrients?

there's no correct ratio. The issue appears to be that at high alk, coral skeletons may grow faster in some corals than tissue can keep up in low nutrients leading to burnt tips. A ratio is not the answer. But higher nutrients may be needed in some tanks if alk is high.