Brown Residue in Calcium Reservoir

Duncan Tse · Jul 12, 2020

I'm getting some brown residue in my calcium reservoir. Used sodium bicarbonate.

Just wondering what is this and is it still safe to dose?

Smarkow · Jul 13, 2020

BRS did a series on which supplements mixed pure and which ones had some residue.
Kinda long but is in-depth. Which brand do you use, and how long since you last rinsed the container?
Good luck and happy reefing

homer1475 · Jul 13, 2020

Also curious what brand of supplement your using?

I have always used BRS brand CAL, and have never had any "residue" in my reservoir.

CindyKz · Jul 13, 2020

I use Seachem Reef Fusion 1 and 2, and have been noticing that my Ca solution has been turning brown in the dosing bottle while it remains clear in the sealed bottle. Haven't noticed any adverse effects in my tank but it is concerning. Following along.

Duncan Tse · Jul 13, 2020

My bad this wasn't sodium bicarbonate but it's calcium chloride purchased from reef supplies in Canada

RS Bulk 2-part *true purity dosing system (makes 10 x 1 gallon - 5/5)

Bulk 2-part dosing system (makes 10 x 1 gallon)

www.reefsupplies.ca

I probably haven't rinsed this container in about half year but not sure if this will cause the brown sludge forming

Smarkow · Jul 13, 2020

My guess would be that this is some sort of oxidized impurity that is not soluble, and it’s been building up over time. Can you siphon it out of the bottom of the container into a waste area?

Duncan Tse · Jul 14, 2020

Smarkow said:
My guess would be that this is some sort of oxidized impurity that is not soluble, and it’s been building up over time. Can you siphon it out of the bottom of the container into a waste area?

Yes it can be siphoned out easily. Would you say this is harmful to my tank? Not sure if I should replace it or not

Randy Holmes-Farley · Jul 14, 2020

Duncan Tse said:
Yes it can be siphoned out easily. Would you say this is harmful to my tank? Not sure if I should replace it or not

It is not uncommon to find a brown precipitate in some types of calcium chloride. I suspect it is iron oxide, but do not know for sure. Folks have not noted a problem with it.