Evaporation rate

[Crackem]

I have a 72 bowfront with a wet dry that is basically my sump since I removed the bioballs and added a gsm mini g skimmer. I've had this tank and sump for over 10 years and have always had a mechanical horizontal float switch which was drilled at the waterline in the sump. The tubing to the float switch is hooked up to my RODi so when the water evaporates it just replenishes as needed. I would like to start using a doser to drip kalk but I'm not sure how much or how often to drip. How do I figure out my evaporation rate?
Should I shut the RO off and add 1 gallon of RO water and see how long it takes for it to evaporate? If it takes 1 day or 2 days do i just drip the same amount back in? Also i plan on using 2 tsp per gallon of rodi. when the jug is empty do i clean it out and mix up a new batch or do i just refill 2 tsps wiith rodi and let settle. Thx for any input.

[bertoni]

The problem with tat type of setup is that an RO/DI filter will produce fairly dirty water when it is first started, so they should be run for a while, not in short bursts. I'd switch to using a still container, as you suggest, but you'll have to do some experimentation to compute the evaporation rate. You could switch over, and see how long it takes for a container to evaporate.

In addition, I wouldn't trust a float valve with Kalk, if that's what you have. I am confused, because a "float switch" usually is an electrical switch, but I am not sure what you have. For Kalk, the safest approach is a peristaltic dosing pump, in my opinion.

[Crackem]

I have a horizontal mechanical float. It's not electrical. I would like to switch over to a reservoir but I'm not really sure if I could do it myself. What I plan on doing is mixing a gallon of RO/DI water and 2 tsps of mrs wages and use a Drews doser. I was planning on just leaving the top off the way it is but dose the kalk simultaneously. I just don't know how much kalk to drip and I don't want to overdose. My tank does not consume a lot of calc or alk. Right now I'm dosing brs 2 part but my ph hasn't gone over 7.9 in over a month. I've been adding more and more sps frags so I thought raising ph to 8.2 would be better. Is that true?

[bertoni]

I think that pH at 7.9 is fine. Raising to 8.2 might in theory encourage more stony coral growth, but I suspect the difference would be minimal. I'd leave well enough alone, personally.

[Crackem]

Sounds like good advice as usual I think I'll leave it the way it is. I was just getting worried cause my lab grade ph probe has been reading 7.71-7.9 and It was reading 7.9-8.1 before I did my last 2 water changes. All other parameters have been well within normal ranges. Thank You again for your advice.

[bertoni]

You're welcome!