dosing with top off

Hey all,

I was testing my tank the other day and I noticed my levels are a little out of wack...i've seen a little downfall in the overall appearance of my tank. But nothing to worry me, everything looks fine.

I was wondering if it's possible to add everything I need to my top off water (necessary amount of Ca, Mg, Alk to bring levels to par) and then use that to top off my tank?

Are there any ill effects to doing this? I use the following. Alk: NaHCO3 (sodium bicarb), Ca: CaCl (calcium chloride), Mg: mix between MgSO4 and MgCl (mag sulfate and mag chloride)

Thanks!!!

 

Oh yeah, I do that all the time.

 

hell yeah!! ok good, i was just making sure!! Thanks John

 

I use Kent Marine's OSMO prep in my top off. Luna

 

The additives can combine in the top off bucket differently then they would in the tank. I know somethings you can't mix - not knowing which you can and can't would make me cautious.

I use Brightwells Kalk +2 in my ATO bucket, which is calcium, magnesium, and strontium

 

If you are using something like a 2-part solution you might want to reconsider. If you combine the alkalinity and calcium prior to putting them into the tank (like into an RODI reservoir) a lot of the product in the water could precipitate out as calcium carbonate in an unuseable form to the coral. The chemistry in the tank is so much different than in RO water that you may be losing a lot of the supplements that you're paying good money for. It's the reason why it comes as 2 part solutions and not one all-in-one additive. I believe PH and the temperature in the tank especially allow the supplements to stay in solution and not precipitate out before the coral can use them.

Kalkwasser is about the only thing I'm aware of that adds alk and calcium in the proper quantities that can be done via auto-topoff. I'm not familiar with the kalk+2 product or the kent OSMO product.

Just my experience.

 

Would you (or someone else) please elaborate on this point?



I have been adding my BRS two part to my top off water. A 3 gallon bucket of top off water lasts me two days, so I put two days of 2 part worth into the bucket.

 

I am not an expert or anything, I just know what I've read by people that seem to be pretty well respected in the hobby. If anyone can clarify or correct anything I'm stating here please feel free. Most of my understanding of chemistry has come from reefkeeping.com and advancedaquarist.com, although I tend to gloss over the technical chemical reactions there is usually a reasonable summary or text description of what that actually means.

This article explains it. I pulled a clip of it that I think pertains most to your question. Basically 2 part is a supersaturated solution, and without the other chemistry in the reef tank (magnesium, phosphates, temperature, ph etc) which prevents the calcium and carbonate molecules from bonding immediately you might get some early precipitation of calcium carbonate which corals can't use, they need the molecules separately in solution in order to create their skeletons.
Calcium and Alkalinity by Randy Holmes-Farley - Reefkeeping.com