Solving a Low Alk Issue

goldenhurricane2 · Apr 6, 2018

Recently I've seen several of my hard corals receding and losing their color, but all my parameters were reading fine... unfortunately, my Red Sea Alk test was nearing expiration (a few months away) and was giving me a false reading. It was showing that my alk was at a comfortable 8.4 dKH. So, after a couple of weeks of trying to figure out the issue, I finally took my water in to a LFS and had it professionally tested. Everything matched up with my tests (or pretty dang close) except for alk - it showed that my alk was sitting at 4.7 dKH... totally explains my issue with my hard corals.

Anywho - I've raised my alk over the past few days according to the calculator on brs, dosing around 20 ml per day to raise it around 1 dKH per day. After I dose this evening, it should be back to an acceptable level. However, my question is: will this large dose of alk have any negative affect on my Ca or Mg? I've been dosing small amounts of Ca along with the alk just to make sure it stays stable, but I haven't added any Mg.

Ca is sitting at 425ppm
Mg is around 1300ppm

Thanks for your help with this - I'm relatively new to dosing as I've been able to keep my parameters stable for over two year by just doing frequent water changes, but I suppose my uptake is finally catching up with me.

slayerhellfire · Apr 6, 2018

so whats it at now??

slayerhellfire · Apr 6, 2018

mag is fine, but your ALK is really low if thats a correct number. Yes it will impact your other levels but you got to get that up sooner the better but not too fast. You sure its that low seems little too low given your other values. Whats your PH at then??

Randy Holmes-Farley · Apr 6, 2018

No, raising alkalinity from 5 to 8 dKH using a measured amount of bicarbonate or carbonate should not alter calcium or magnesium. It will allow consumption of all of them (both biological and abiotic) to resume.

goldenhurricane2 · Apr 6, 2018

Randy Holmes-Farley said:
No, raising alkalinity from 5 to 8 dKH using a measured amount of bicarbonate or carbonate should not alter calcium or magnesium. It will allow consumption of all of them (both biological and abiotic) to resume.

Ok great - that's what I was hoping to hear. Thanks!

goldenhurricane2 · Apr 7, 2018

Randy Holmes-Farley said:
No, raising alkalinity from 5 to 8 dKH using a measured amount of bicarbonate or carbonate should not alter calcium or magnesium. It will allow consumption of all of them (both biological and abiotic) to resume.

Ok so my alk level has been raised up to an acceptable level. How long do you think it’ll take for some of my hard corals to regain color?

Randy Holmes-Farley · Apr 8, 2018

goldenhurricane2 said:
Ok so my alk level has been raised up to an acceptable level. How long do you think it’ll take for some of my hard corals to regain color?

I'm not sure they lost color due to the low alk, but if they did it may take a substantial period.