puzzling calcium

[rmanecke]

When I first tested, no supplementation, I found Ca levels of 330 ppm. pH 8.2 to 8.4.

I dosed with Kent part A and B, 15 ml each for 70 gallons of water, daily. After a week I was able to bump up to 360 ppm.

I tried dosing at lights out and early a.m., still stuck at 360 ppm, but, I noticed a drop in my alkalinity. So, I think that maybe my calcium test kit is wrong (fast test).

So, I used Haegen test kit last night... Haegen says 400 ppm, Fast test now reads 345 ppm.

I need a tie breaker.

Any ideas? Salifert? Magnesium tests?

Ryan.

 

[reefman23]

I know that Salifert are usually the most accurate, but FastTest should be pretty accurate as well. I dont know much about the Haegens. Maybe an average of the two...~375? haha.

What Kind of corals are you keeping?

Jesse

 

[EDGRAY]

Well we should change some parameters cause i have really high alkalinity and calcium but low ph :lol: :lol: Anyways i dont trust the A & B thing why??? cause you dont know for sure how much of each element your are adding so you should stick on thing saparetely like bio-calcium, bio magnesium, iodine, strontium etc etc,..... and you'll under control cause you will now what needs to be dosed and what doesnt but anyways that's my opinion good luck. about the testers thats kind of odd... and well testing with to testers is always a great idea i do quick dip and liquid testers.

 

[rmanecke]

Jesse...

Well, I am keeping some open brains, mushrooms, hammer corals right now. I plan to add some more hammers and frogspawn this weekend.

Eventually, I would like to add some squamosa clams, and will need the Calcium issue resolved by then.... goal Ca would be about 400 ppm I think.

Ed...

I thought that really high Caclium levels were generally incompatible with really high alkalinity levels. This is why I became suspicious when my Alk dropped that my Ca was going up. pH is stable at 8.2 - 8.4.

Anyway... also being a little suspicious of the part A and B routine....

I added a little Kalk to my top off water today... will retest with all kits tonight and retest.

Thanks.

 

[leakyfaucet]

Depending on the type of calcium you are using, it might screw up your alkalinity. For example, I think some calcium supplements might have carbonate added to the solution, giving you Calcium biCarbonate. Ca(HC03)2 is temp sensitive, so depending on your tank temperature it mighjt have driven the reaction in this direction ---> CO2(g) + H2O(l) + CaCO3(s). releasing C02 which in solution is acidic, which could explain the drop in pH. I would think that your saltwater would have been able to buffer that though, and you said pH Stabilized so it looks like that's what may have happened.

 

[rmanecke]

well tonight... after adding a little kalk (one tsp in 2 gallons, about 1 gallon went into the tank through the ATO - small dose, I know), plus, I added the usual dose of Kent A and B

pH 8.2 - 8.4 (stable)
alk 3.5 mg/L (stable, started out at 4.0)
calcium 345 (by the lower reading fast test kit)

I ordered a salifert kit for Calcium and Magnesium. Maybe mag is very low?

 

[rmanecke]

Well, here it is, the calcium test showdown...

Salifert = 450ppm
SeaTest = 375 ppm :wh
Haegen = 440 ppm

and... checked the Mag levels

Salifert Magnesium=630ppm (sea water is about twice this)

The salifert test is by far the easiest to use and read.... I'm going with that one. Also, it seems that I should raise the Mg level. For those who keep track.... what is the goal? Over 1000ppm? Over 1400ppm?

 

[skipm]

the target range is usually as near or slightly above natural seawateras possible.

 

[rmanecke]

OK, that helps. I just read that low Mag can cause some problems for hammer corals (which I have)... off to buy some Mag at the LFS!

R

 

[rmanecke]

OK. Bought some Mg. Adding to raise Mg levels by 15 ppm per day... goal 1200 ppm. It will be interesting to see how this affects the appetite of the tank for two part ionic.