Advice? 2 part dosing

Hey guys -

I have a question about 2-part dosing. I have been struggling for about 2 months with 2-part dosing - trying to get my levels of alkalinity and calcium correct.

My first question: how many mL/day do people dose? I am currently running mine at 120mL/day, which seems a bit high, doesn't it? My tank is a 125 gallon tank with a 40 gallon sump. So maybe 130 gallons of water total when taking rock/sand into account? That just seems like a lot?

I am using the BRS 1.1 ml/minute dosers. I am dosing soda ash twice a day, once at midnight (60 mL) and once at 3am (60 mL). I am then dosing calcium at noon (60 mL) and 3pm (60 mL).

My results so far haven't been great. My alkalinity seems to be staying in the correct range, but my calcium keeps dropping. Using the Red Sea test kits, here are my results:

Wednesday 3/28
Alkalinity - 8 dKH
Calcium - 420 ppm

Sunday 4/1
Alkalinity: 9 dKH
Calcium: 360 ppm

Where should I go from here? Somebody told me at one point that you should dose the same amount of soda ash as calcium since they are supposed to balance each other out. But this doesn't appear to be the case for me?

I tested magnesium on March 16th and it was showing 1400 ppm, so a lack of magnesium shouldn't be a problem?

I do weekly 15-17 gallon water changes using Red Sea Pro Salt.

My other numbers (in case they are relevant):

SG: 1.026
pH: 8.21
Dissolved Oxygen: 8.2 ppm
Temperature: 78 F
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 10 ppm
Phosphate: 0.10 ppm

My RODI water I use is measuring 0 ppm TDS.

AM I dosing too much solutions? Should I lower the soda ash and leave calcium where it is?

Any suggestions would be appreciated.

 

I have a handful of stony corals - nothing too crazy though. And no clams. I am using the Red Sea test kits for alk/calc/mag.

I left calcium where it is and lowered the soda ash to 80 mL/day to see if that makes a difference. Do you think that I should manually dose calcium to try to bring it back up to 420?

I also have a couple of stony corals that are dying off and bleaching. Could the swings in alk/calc be killing them???

 

Hey everybody. Thanks for the replies....

I am still having some issues with this, but I decided to make a few changes and see what happens....

Somebody had suggested dosing more often and in smaller amounts, and also alternating between alk/calc to prevent swings. So here is my new schedule:

12:00am – Alk
3:00am – Calc
6:00am – Alk
9:00pm – Calc
12:00pm – Alk
3:00pm – Calc
6:00pm – Alk
9:00pm – Calc

I also noticed there was a potential problem with my calcium container not having a hole drilled into the top so the pressure inside it may have been causing it to not dispense the correct amounts.

I have cut it down to 80 mL/day for each as well to see if perhaps I was overdosing.

And I ordered a different brand of test strips to make sure that the results I am getting are accurate.

Almost all of my stoney coral has died. I can't be certain if the alk/calc swings were the culprit, but that is the leading candidate right now...

Once my new test kits get here, I am going to start testing twice daily so I can really try to hone in on what is happening...