Need help stabilizing chemistry

[servus]

75 gallon mixed reef tank, 15 months old, can't seem to get chemistry stable on it.
Dosing RedSea two part for about 3 months, can't get good values on pH, Ca, Mg.

Ph:
- testing with calibrated Vivosun tester, 7.7
- testing with Hanna checker, 8.5-8.6

Calcium:
- API test kit
- fluctuating between 380 - 450, depending on... who knows what?
- dosing 12+10+7ml per day, today I changed to 12+12+12

Magnesium:
- RedSea kit, two kits measuring same values, both kits tested with a verified Mg sample, both kits measuring accurate
- measured 1050, started dosing slowly, 5+5ml, then upped to 5+5+5, now I am at 12+12+12
- at one point dosed 200ml, Mg raised to 1300, can't maintain it!!!
- I was afraid of dosing Mg too much, as I see concerns everywhere that once you have too much Mg, it won't go down

Alkalinity:
- my most stable parameter 9 - 9.5
- checking with API kit and Hanna checker

Please help with Mg/Ca/pH. My corals are growing, not as fast as I see in youtube videos, I am afraid Ca/Mg/pH are not ok. Can you help me?

 

[chadfish]

I don’t know much about stabilizing reef chemistry, but I do know this:

Don’t compare your tank to YouTube or anyone else’s tank. Corals grow slowly. Health and stability are paramount. Also, it seems like most of the time, the answer in this hobby is “do nothing and monitor”

good luck, I bet someone here can help you

 

[blasterman]

Your calcium is not bouncing around between 380 and 450. You would need a 2.5 gallon tank full of SPS for that to happen.

Its either testing error or testing error. Given you are using API I suspect testing error.

Get the Red Sea calcium test and you will see calcium isn't moving much at all. You just think its moving.

A 75gal tank literally has buckets of magnesium in it. The reason it isn't changing is you are adding fractions of a gram of magnesium at a time. You would have to add a lot of straight magnesium chloride to a 75gal to even see a difference in saturation with any reef grade test kit. Magnesium depletion is always a small fraction of calcium depletion.

The fact your alk is stable says a lot. Means your other params have to be stable. It is physically impossible for calcium and mag to bounce around if alk is stable, and your alk is being verified with a Hanna.

 

[servus]

All you guys say makes lots of sense, thanks for reinforcing my thoughts!!!
I read and read and can't wrap my head around it. The Ca is not literally bouncing, just can't seem to get it to 430 stable. I should send the charts out for you to see.

 

[servus]

See images for test records.

 

[Fennel]

I don’t know much about stabilizing reef chemistry, but I do know this:

Don’t compare your tank to YouTube or anyone else’s tank. Corals grow slowly. Health and stability are paramount. Also, it seems like most of the time, the answer in this hobby is “do nothing and monitor”

good luck, I bet someone here can help you

Exactly.. do nothing when there is nothing to be done, do something to save yourself if something bad sprouts. I would rather enjoy a cloudy reefscape from mag sulfate, cal and soda ash.. than have to clean up fish crap and spot feed coral. I do have another tank with feather dusters, which are truly beautiful creatures and fun to watch twirl, don't get me wrong.