Reef Central Online Community - View Single Post - Let's talk about Alkalinity, Calcium and Magnesium in an SPS Tank

Sk8r · 08/08/2007, 09:24 AM

This is what I know about supplementation: if you hand-dose, you need to test at the same time every day to try to minimize the swing. I got into serious trouble letting an unstirred 7g ro/di bucket do my alk supplement. Bad idea. That let to, eventually, a buildup that finally got dosed when the bucket ran low: hence the spike.

A kalk reactor, supplying both alk and cal, can contribute to ph problems, but I can say my gallon + a day evaporation rate and small tank size [54g] makes an ideal situation for kalk as THE supplement---so far. Corals can get very hungry, and once the fast-growing montiporas really get started, it may be different, but right now the reactor will hold the 54g steady with only set-up dosing.

Some people run both a calcium reactor AND kalkreactor.

And stability I'm sure is a big item in the benefits. That and precipitation of phosphate via kalk [unproven, meaning I've never found any article with research] but...my tank algae is going away.

Does anybody know whether the ocean has 24 hour cycles in ph, alk, cal? Is there any net effect of dark period and coral absorption cycles re the condition of the water in the immediate surrounds of a reef?

08/08/2007, 09:24 AM	#20
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	This is what I know about supplementation: if you hand-dose, you need to test at the same time every day to try to minimize the swing. I got into serious trouble letting an unstirred 7g ro/di bucket do my alk supplement. Bad idea. That let to, eventually, a buildup that finally got dosed when the bucket ran low: hence the spike. A kalk reactor, supplying both alk and cal, can contribute to ph problems, but I can say my gallon + a day evaporation rate and small tank size [54g] makes an ideal situation for kalk as THE supplement---so far. Corals can get very hungry, and once the fast-growing montiporas really get started, it may be different, but right now the reactor will hold the 54g steady with only set-up dosing. Some people run both a calcium reactor AND kalkreactor. And stability I'm sure is a big item in the benefits. That and precipitation of phosphate via kalk [unproven, meaning I've never found any article with research] but...my tank algae is going away. Does anybody know whether the ocean has 24 hour cycles in ph, alk, cal? Is there any net effect of dark period and coral absorption cycles re the condition of the water in the immediate surrounds of a reef? __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.