Can substrate effect alaklinity and calicum consumption?

Swaefa · May 30, 2018

Currently I am running two tanks, 70 gallon and 80 gallon. The main difference is one is bare bottom and the other has crushed coral. The consumption of calcium and alkalinity is very high compared to the 70 gallon tank. The parameters are as follows

70 Gallon Tank bare bottom primarily zoas and 6 fish
pH 8.3
alk 8.7
cal 450
mag 1450

Using ME for supplements. Dosing 94ml cal, 52ml alk, and 39ml mag.

80 Gallon Tank crushed coral bottom primarily LPS, small clam, 7 fish.
pH 8.2
alk 8.1
cal 490 (just reduce dosage by 10%)
mag 1350

Using ME for calcium and mag supplements Dosing 198ml cal and 40ml mag. Was using ME supplements for alk but the pH was running over 8.5 so I switched to BRS sodium bicarbonate and dosing 321ml. When I was using ME alk I was dosing around 100-110ml.

All dosing is done daily. Mag is dosed over a 24 hr period. Alk is dosed at night and cal during the day. There is a 30min break between the dosing of alk and cal.

CNDReef · May 30, 2018

The clam alone could be the culprit but the lps will also consume more than the softies

Maacc · May 30, 2018

I think you are adding way too much to the crushed coral and have precipitation and deposit issues on your equipment. Do you have white films on your equipment and does your crushed coral feel like it is stuck together?
What you have should not translate into that much demand, I think you are fighting yourself.
I would think you should be at 20-30 ml per day max.
Try to boost your mag to 1400, then stop dosing for a few days then dose very little in balance, test and see what happens.

Randy Holmes-Farley · May 30, 2018

The 80 gallon tank using 321 ml bicarbonate solution per day is adding 2.8 dKH per day. Not super high, IMO.

The 70 gallon tank using 52 ml of ME coral additive is adding about 1.5 dKH per day.

That all seems reasonable to me for the described tanks.

Either tank might have some precipitation, as most tanks do.

Randy Holmes-Farley · May 30, 2018

Maacc said:
I think you are adding way too much to the crushed coral and have precipitation and deposit issues on your equipment. Do you have white films on your equipment and does your crushed coral feel like it is stuck together?
What you have should not translate into that much demand, I think you are fighting yourself.
I would think you should be at 20-30 ml per day max.
Try to boost your mag to 1400, then stop dosing for a few days then dose very little in balance, test and see what happens.

You need to check the product used. 20 ml of the bicarbonate product in 80 gallons is only 0.35 dKH per day, which is not that much, IMO.