Acceptable kH/Ca drop? When to start kalk?

[puffy127]

I think I have a pretty light coral load, with just some hammers and a few monti caps. Been getting away with just weekly 18% water changes with RC, but am wondering at what point would I need to start using kalk? After a water change, my alk is at 138 ppm (7.7 dkH) and after a week, it is around 131 ppm (7.3 dkH). My Mg doesn't change much before and after water changes and is around 1485 ppm. Ca levels after a wc are around 500 ppm and come down to 450 ppm after a week. I have never dosed anything or added any supplements, this is just from RC.

How exactly does kalk stabilize the parameters without increasing the levels even more than they are? I think my Mg and Ca levels are a bit high, so I wouldn't want them to go any higher.

 

[cjd]

Kalk is used to maintain your Alk and Ca not really to increase them. Its used in ATO systems and constant drip methods. If you are using reliable test kits that you trust are giving you accurate readings then the kalk would keep those levels at 7.7dkh and cal at 500. The trick is to find the right mix of kalk to rodi water to keep things stable. In your top off water that you use for daily evaporation I would start out with 1/2 a teaspoon to 1 teaspoon to a gallon of rodi. Mix it up and let it settle for a day . I don't know how your system is set up so you would either use that as your ATO reservoir or what I do is a constant drip method to where I calculated the amount of evaporation so I don't flood the tank and I have a constant drip 24 hrs. a day 7 days a week constantly filling my tank as the water evaporates. You will want to test once before you start the kalk and maybe couple days after to see where your numbers are at . If they are increasing use less kalk in the make up water. If they are decreasing , add more , up to 2 teaspoons. If the kalk doesn't keep up with your tanks demands consider switching to a two part system.

 

[puffy127]

So would the goal be no drop in alk and Ca at all? And kalk in my ATO can achieve this?

 

[cjd]

Perfect world. ..yes , no drop. With your bio load as of now, kalk will do the trick. As you increase your coral load the need for more supplements will increase as well. Testing will tell you when Kalk can't keep up with the demand of alk and ca. All tanks are different and consume things at a different pace.