Increasing calcium without increasing DkH too much

lilbitreefer · Oct 31, 2018

So I have been neglecting my calcium and alkalinity. I have been dosing two part at 20ml/day. I have a maxima clam and a small stony coral so I didn;t think it would be taking much. I started out with a Ca of 435, 10.25 alk, 7 weeks later my Ca is 377 and alk 8.96. I just went to the BRS website and it wants me to dose 529 ml of calcium chloride to get it back to 420. The dkh is already high and I am not sure how to dose both of them. dosing equal amounts of soda ash would probably send the pH and the alk through the roof and fry everything. Right now I am following melevs reef's advice to split the ca and alk dosing to 12 hours apart and found a bit more stability in my tank.

I did some math and determined how much the parameters were decreasing per day and came to the conclusion I needed to add 33.3 ml of two part daily just to maintain. I have set that on my apex but now I am not sure how I to raise the Calcium to a bit better level without shooting the pH way up.

My magnesium levels are 1425 if that makes any difference. I noticed that this might be a bit high and have since changed my dosing schedule to from 20ml daily to 5 ml daily. I prefer to maintain daily levels then trying to replenish every few months. Maybe I have it wrong, but that is my thought process right now.

The pH daily swings have been maintaining 7.89 as a low and 8.1 as a high throught out the day.

Anythoughts anyone? Should I just make it even and dose 50ml each for a week and recheck parameters to see if it's working? Or risk frying my tank with one big dose to increase the ca.

WWIII · Oct 31, 2018

I would dose more calcium until it reaches the level you're shooting for. Then when you reach that level go back to dosing equal parts. You don't have to dose them in equal parts if the tank is out of balance.

lilbitreefer · Oct 31, 2018

Thats what I was worried about cause I've always been told to dose equal parts, BRS says I could dose the entire 500 ml now without causing the calcium to raise more than 50 ppm in a day. I guess I could schedule it to dose over the night.

Martin Kuhn · Nov 1, 2018

50ppm per day is a lot.
As Ca does not drop as fast ... my recommendation would be 20..30ppm/day to bring the levels up to where they should be.

lilbitreefer · Nov 3, 2018

I did only dose about half of what BRS advised and it raised it to 550.

Randy Holmes-Farley · Nov 3, 2018

In general, it is perfectly fine to dose calcium chloride or the calcium part of a two part, to make any size correction you want, and not dose any alkalinity. I'd limit the calcium rise to about 25 ppm per day to limit the sudden inrush of impurities that might be in it.

550 ppm is fine and I'd just stop dosing the calcium part for a while.

lilbitreefer · Nov 3, 2018

Well here’s another plot twist, I just rechecked my calcium and it’s back to 374. Alkalinity 9.17. Any thoughts on what to do?

WWIII · Nov 3, 2018

lilbitreefer said:
Well here’s another plot twist, I just rechecked my calcium and it’s back to 374. Alkalinity 9.17. Any thoughts on what to do?

Do you have another test kit to double check the readings?

Randy Holmes-Farley · Nov 4, 2018

lilbitreefer said:
Well here’s another plot twist, I just rechecked my calcium and it’s back to 374. Alkalinity 9.17. Any thoughts on what to do?

I agree with the above post . It's likely to be testing issues. Calcium does not jump around like that. Real calcium demand is unliokely to be more than about 20-30 ppm per day, and for a 20 ppm drop, you'd need to also see an ~ 3 dKH drop in alkalinity. For the 175 ppm drop in calcium, the alk would need to drop by about 26 dKH.

lilbitreefer · Nov 13, 2018

I rechecked the Ca a day later and it said it was greater than 600 with a alk around 9dKh, got busy with work so returned dosing 33ml day. I got some distilled water since I realized I grabed fresh RODI water from the barrel I generally mix my salt in instead of my fresh RODI only water. Maybe that is where the high reading was from. I rechecked yesterday Ca 377 and Alk 10.19. Instead of high dosing I started dosing at 40 ml/day. I also just added some new SPS frags and they all seem to be happy and open right now. I will recheck Ca in a few days maybe another week and see where it is trending. I am running low on Ca reagents so I am trying to make it last until the BRS black friday deals for test kits to get more reagents. Here a pic of one of my new frags.

lilbitreefer · Nov 13, 2018

Oh not sure if this is a problem either, I checked my magnesium as I as dosing 5 mL a day as a means to keep up with magnesium loss. seems I have over dosed mag. the reading was over 1500 I used all the reagent in the syringe so I have no idea how high it truly is. Long story short I have quit dosing mag.