DIY Calcium Additive?

[smhray]

Hey everyone! I started dosing kalkwasser about a week ago and my calcium levels have still been declining. My alkalinity is pretty stable but my magnesium is also a bit low. I was planning on dosing epsom salt (magnesium sulphate) and also calcium chloride to help with these parameters. Does anyone know if I can use Dowflake Xtra 83-87% pure calcium chloride in my tank? I would love to use this since it is much more cheaper than any other option here in Canada. Also, is there anything I should look out for with epsom salts or will any basic kind will do? TIA for any input.

Tank: Reefer 250, mixed reef around 50% sps
Params:
Alk: 7.7dkh
Mag: 1250ppm
Calcium: 340 ppm
Salinity: 1.025
pH: 8.0 (I also used the kalk to help me raise the pH, it was sitting at a constant 7.8 before)

 

[Randy Holmes-Farley]

Most likely that is test error.

To have happen what you report would require some other source of alkalinity as there is no scenario where kalkwasser oversupplies alkalinity relative to calcium when demand is from production of calcium carbonate.

Water changes can boost alk, as can declining nitrate or nitrate dosing.

Assuming you believe the calcium number, I'd boost it to 420 ppm with calcium chloride over a few days.

 

[smhray]

Most likely that is test error.

To have happen what you report would require some other source of alkalinity as there is no scenario where kalkwasser oversupplies alkalinity relative to calcium when demand is from production of calcium carbonate.

Water changes can boost alk, as can declining nitrate or nitrate dosing.

Assuming you believe the calcium number, I'd boost it to 420 ppm with calcium chloride over a few days.

Hi Randy thanks for the reply. My main question was what diy calcium chloride could I use instead of paying so much more just for the "for aquarium" label. Would Dowflake Xtra 83-87% pure calcium chloride be safe in my tank? And also can I use any kind of epsom salt in my reef?

 

[Fennel]

Seriously straight calicum carbonate, (plain antacid) epsom salt mix holds alkalinity. What do you think reefers did 30 years ago in a pinch? Epsom salt raises salinity... (Ducks out of the way before the debate starts) that and cheap fountain pumps for water movement.. it's like save a cent now, you might pay more later.. whatever works.. wink. Do your research. Ask a boomer..

 

[blasterman]

Epsom salts are magnesium sulfate, so they won't raise salinity. Even if you use magnesium chloride which theoretically will raise salinity you would have to dose an absurd amount to show up.

I've used calcium carbonate powder (dietary supplement with a consistency like flour) as an experiment to see if it had any advantages over calcium chloride. It turns your tank to milk, but dissolves in a few hours to nothing. Per weight it has a bit less calcium boost than calcium chloride, but still works. It also pulls down alk a tad. Interesting experiment that shows how corals don't care what flavor calcium comes in, but regular calcium chloride is just as cheap and more convient.

 

[Randy Holmes-Farley]

Epsom salts are magnesium sulfate, so they won't raise salinity.

Yes, it does. Any solid material counts toward salinity.

A 50 ppm boost to magnesium using magnesium sulfate boosts salinity by 248 ppm or 0.25 ppt.

 

[Randy Holmes-Farley]

Hi Randy thanks for the reply. My main question was what diy calcium chloride could I use instead of paying so much more just for the "for aquarium" label. Would Dowflake Xtra 83-87% pure calcium chloride be safe in my tank? And also can I use any kind of epsom salt in my reef?

Epsom salt can easily be obtained USP from a drug store, so that is fine.

The dowflake is very likely fine.

 

[Randy Holmes-Farley]

Seriously straight calicum carbonate, (plain antacid) epsom salt mix holds alkalinity.

I'm sorry, I'm not following what you intend that to mean.

Calcium carbonate is not a very useful supplement unless you dissolve it somehow. It won't dissolve in a reef tank.