calcium consumption more than normal

[jstncoffman]

hello all, lately i have had a big difference in calcium consumption more than normal. I have confirmed the results with three different types of test brands also took a average of 3 tests to confirm. My trident is within +/- 20 ppm of these results. checked for precipitation on heaters pumps etc., nothing. all is clean and normal. dosing B ionic 14mls a day and also alk 8 mls a day. AWC is 1 gallon a day with TMP salt. The salt is mixed at 35ppt every 2 weeks, confirmed the levels of the salt after being mixed. ALK 7.8 (average) CAL 415 (average) mag 1250 (average). nitrate is always a solid 13.5 to 12.5 , phos is always .02. feeding is always the same time and schedule and amounts. ph is also always around 8.1 to 8.2 depending on time of day with Fuge light to offset. tank is mixed reef mini colonies and frags. corals look happy except SSC acro is turned all a light purple with small polyp extension. lighting is a XR30 pro gen 5 with reef brights.
for some reason my cal is dropping to the lower 400s to high 300s over a coarse of 3 days to a consecutive weeks. Alk and Mag are solid no fluctuations out of normal. if anyone has some helpful advise or has seen this as a norm please let me know. In 20 years of reefing never seen this type of a Cal swing or consumption VS alk. all other corals are very happy. also to help aid in the situation i was dosing equal parts of ESV for over 2 months with no issues this has been a trend for over 5 weeks now and would hope to catch the issue early thank you in advance

 

[Randy Holmes-Farley]

" dosing B ionic 14mls a day and also alk 8 mls a day"

What does that mean exactly?

Assuming the test result are accurate (always a risky assumption; try the kits on some new salt water), and assuming the above statement means 14 ml of the calcium part and 8 ml of the alk part of B-ionic, then
I expect your not dosing as much of the calcium part of the B-ionic as you think (or more of the alk part).

There is just no possible mechanism for calcium to be consumed without alkalinity being consumed at a ratio close to 18-20 ppm calcium for each 2.8 dKH of alk.

Assuming no other sources of alk in your system (dosing nitrate and tap water are possibilities), then even your stated dosing ratio suggests a dosing measurement problem.