What happened? (precipitation event)


New member
A little background on my procedures. I have been using Kalk in my top off for well over a year now with no issues. In a 5 gallon container I use 2 tsp per gallon of RO/DI water. I'm trying to get away from dosing 2 part once a week and I know the Kalk can never replace this but it's pretty dang close. So I decided to try saturating the top off water by following the recommended 45ml per gallon but I cut it in 1/3 and only used 1.5 tsp extra of kalk. I stirred up the mixture like usual and let it sit overnight to settle the fines. My doser runs for 35 min to top off roughly a gallon of water per night.

Last night I had the biggest snow storm I have ever seen in my reefing history. I couldn't even see 3" into the tank. I also have a couple dead snails due to the event last night. It was bad. It looked like a tank of milk. I threw the skimmer into overdrive to start skimming wet and I threw on a 50 micron filter sock to help catch the fines and by this morning it finally settled. My glass is coated in calcium precipitation, my rocks look like they have been snowed on. What exactly happened last night with 1.5 extra tsp of kalk? Did I reach critical mass? Lol. Everything else seems fine in the tank and all inhabitants minus a couple snails are accounted for. Params were always right on target (450 cal, 9 Alk, 1400 mag) before this and I haven't had a chance to test my water this morning but I would like some ideas of what caused this. Thanks.

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Water Lover
When did you do your last water change and how much did you change? It sounds like you may have had an imbalance that tipped over with the dosing, but your levels appear to be good, so it is strange indeed. I assume you had no precipitation before last evening? How much of the two part are you currently dosing?


New member
I would not get one bigger than a 100mg a hour for a tank your size because if something goes wrong with the ozonizer and it spits out at full volume you don't want to kill/ruin stuff. I have about 250 gallons of water volume on mine and I have a 200 mg ozonizer and don't run it on full.


Premium Member
The kalk dosing might have been too much, or the vinegar might be causing a bacterial bloom. If the alkalinity has dropped a lot, I'd guess the kalk caused a precipitation event. You might have been at the tipping point in terms of the rate of dosing.