precipitation

[spscrackhead]

I believe I am having issues with precipitation in my 75 gallon. Although I am showing no visual signs (no build up on heaters or pumps, no clumpy sand) these numbers just don't add up!
My tank is not mature and has about 15 lps frags and 20 sps frags. The sps is growing nicely I see visible signs of growth. Corraline is taking off and I need to clean it from the glass weekly.
Attached are images showing my levels and what I currently. Brs 2 part and pharma kalk from a reactor. The vinegar is dosed in to the reactor to concentrate the kalk.
I have done the stop dosing to try and stop the precip (measure alk drop and calculate demand to formulate a proper dose) but alk drops rapidly and I am trying to not kill my sps...
Any tips would be appreciated.

 

[spscrackhead]

Alk 7.95 (goal 9)
ca 420
mag 1406
Ph 8.1
I dose 1300 ml kalk
40ml vinegar
275 alk
250 ca
Temp 78.8-80

Also, do calcium reactors have precipitation issues? I have a geo 618 from a previous tank and have been considering setting it up. If the answer is no, ca rx do not lead to precip issues like the soda ash, I may buy the regulator and setup the reactor.

 

[bertoni]

You are dosing 275ml of the alkalinity supplement per day? If so, I would try switching to baking soda for a few days. The lower pH will lower the abiotic precipitation rate, if that's the problem.

 

[spscrackhead]

Yes correct, per day.

 

[bertoni]

That's a very large amount. I would try baking soda. It should be similar in its effect on precipitation as a calcium reactor, but easier to try in the short term, and very cheap.