Added way too much kalk water, but calc/alk actually drops.

[reefsmurf]

So yesterday I measured my water and it came out to be 2.06 meq/L alkalinity and 327.5 ppm calcium. Normally people recommend ~2.5-3.5 alk and 400-425 ppm calcium, so I was really on the low side. I use salifert test kits.

I normally drip kalk water at night (automated).. so today I decided set it to drip during the day as well to try to boost my levels. I left it on too long and the pH of my tank rose to 8.7. oops.

Anyway, I measured the water immediately afterwards and the measurements actually dropped compared to yesterday at the same time. Now I'm at 2.0 meq/L and 300 calcium.

I have a 29g tank with not that many SPS and no clams. Who stole my calcium and alkalinity??

My kalkwater is mixed at 1.5 TSP per gallon (in between the recommended and maximum dosage), and is mixed once a week and dosed in nightly. I have an open top with a fan so there's a good amount of precipitation for nightly dosing.

I should add that I run a phosban filter and it says it will drop alkalinity, but still..

 

[Randy Holmes-Farley]

Raising the pH that much increases the abiotic (nonbiological) precipitation of calcium carbonate. To some extent it may also increase the consumption of calcium and alkalinity by corals and coralline algae. Hence the levels can actually fall when overdosing limewater. That sort of negative feedback is really useful to aquarists because it makes limewater dosing very self limiting, and folks almost never get excessive calcium and alkalinity by dosing limewater for this reason.

 

[Aquadiva]

abiotic (nonbiological) precipitation of calcium carbonate.

Ummm... for those of us who have been out of school WAY too long, would this be the dreaded "snowstorm", or could this just be referring to an excessive buildup on things like heaters. Thanks..

 

[Randy Holmes-Farley]

Both. A huge overdose leads to a snowstorm. But elevated pH in general may increase precipitation on heaters, pumps, etc.