Kalkwasser dosing

[_Mackus_]

I've read several articles (incl. a great one by Randy Holmes-Farley) about dosing kalkwasser as well as searching through several threads about it, and I think I want to begin using this method to keep my alkalinity and calcium stabilized.

I want to double-check to make sure I understand everything, and that my plan will work before starting. So here's my tank specs as well as what I'm planning on doing, based on my understanding of how a kalkwasser dosing system can work. Any comments, critiques, suggestions, or (possibly unlikely) "yeah you're right on the money"s are very much appreciated.

I've got a 125 gallon display which is still only about 7 months old. It's got a 30-gal sump underneath it. I've only got a few small SPS, 2-3 inches or so, not much larger than frags, as well as several larger LPS pieces and a derasa clam so far. I'd like to have a mixed reef, but if that proves difficult, I'd prefer SPS to LPS. My calcium has been pretty stable around 440 ppm, but I can't get the alkalinity to stay above about 7 dKH. I'd like to raise it, and my understanding is I should raise those levels via 2-part or other dosing up to where I want them and then start the kalk dosing.

I top-off via an ATO pump which runs 4 times a day (6 hours apart) for 30 min at a time, and that works pretty well to match my evaporation. Its a BRS 50 ml/min pump, and it's in my basement, pumping up to my living room to the tank. I think without considering head loss, that I'm topping off about 1.5 gal/day, so it's probably closer to an even 1 gal/day of top off water. I currently have the intake to my pump sitting in a 44-gal Brute container, that I have my RODI unit making water into. I also use that water to mix new saltwater. I don't yet have a saltwater container, so I just have a 5-gal bucket with mixed saltwater and a powerhead in it constantly, then when I use that for a water change, I make another.

My plan is to get as large of a container as I can fit (tight on space, so I'm hoping for a 32-gal, but may have to settle for smaller). I'll just add water via a pump (or more likely at least at first, by hand with a 2-gal bucket) from my RODI container to the new kalk container. Then add kalk powder (Mrs. Wages most likely) at ~1 tsp/gal to that. Stir thoroughly, then let rest. I'll switch my ATO pump so that the intake is now the kalkwasser, which will continue to top off my evaporated water at about 1-1.5 gal/day over four 30-min intervals. Hopefully I'll be able to go 2-3 weeks between when I need to refill the kalkwasser reservoir. I'll continue to mix saltwater using only the 44-gal reservoir of RODI, not the kalkwasser.

Any major gaps in my plan or things that I should change? I know it's not the most automated system, but I'd like to avoid buying several additional dosing pumps and timers.

Thanks

 

[Psyops]

Seems good to go. You can adjust the alk anytime though. Some systems do rather well at that level. You will probably have slow growth. If it aint broke don't fix it mentallity. My system is about double from yours. I also have similar type of corals at the same growth level. Instead of starting at 1tsp/gallon start with 2-3 tsp/ 5 gallons. So 1/2 tsp or so per gallon. Check your levels often at first and see what happens. You can go all the way up to 3tsp/gallon. Hope this helps until the big guns start answering your thread.

 

[_Mackus_]

You can adjust the alk anytime though.

Thanks for the response.

As far as increasing the alk, do I do that through going to higher than a 1 tsp/gal dose of the actual powder or should I use an alternate method (2-part, or other supplement) to raise the alk then lock it in with whatever saturation of kalkwasser I end up needing to maintain the levels as I dial in the system?

 

[Randy Holmes-Farley]

If alk needed to go up a bit, yes, increasing the solid lime in the limewater is the best way as long as you can attain that. After 2 tsp per gallon, then you'll need to add another method, like a two part.

 

[Psyops]

On my first system I needed to add the alk separately. On this present system the increased kalk (as Randy just said) did the job. Just try to increase the kalk at first (since this is easier to do) and see what happens.

Do it slowly and check parameters often. Be patient. That was my downfall with my old system. Obviously watch your calcium levels also.

Hope this helps.