RSR 170 Evaporation Question

[AnAngryDruggist]

I’m a little confused by a recent development in my Red Sea Reefer 170 setup. To give some backstory, I’ve been dosing Kalkwasser continuously with the use of a versa pump for about 2 months. I also do continuous auto-water changes with 2 versa pumps. 6 days ago, I increased my Kalk dosage from 0.2 mL/min to 0.25 mL/min because my alkalinity was dropping. I tested alk 48 hours after that adjustment to confirm that my alk stabilized, and it had.

I use an Apex ruler to monitor my ATO reservoir. I noticed that since I did that dose increase on the kalk, my ATO has not dispensed any water. I noticed today that the water level in the sump is higher than usual. I’d say it’s gone up about a half inch in 6 days.

I’m confused because from what I’m reading, my tank should be evaporating a minimum of 1.7 L (1% total volume) per day. The increased dose of Kalk should be adding 360 mL per day, a fraction of 1.7 L.

Is my tank really evaporating that little volume? Of note, I have calibrated all my versa pumps.

 

[blaxsun]

If your RO level hasn't dropped but the water level has increased then it's more than likely something is amiss with your AWC. Either not pulling enough water out or putting too much back in.

 

[CoralFarm]

Keep in mind that evaporation is based on a lot of factors, two of the main ones being the humidity in the room and the temperature. If you're running an air conditioner, that essentially acts as a dehumidifier. If you're running heat, that sometimes dries the air as well which causes your tank to evaporate more.

The number you gave is an average and should only be seen as that. We run about 30,000 gallons at the farm, with about half of that being in a greenhouse and the other half being in a warehouse. Depending on the time of year, my evaporation rate in the warehouse is two to three times that of the greenhouse due to the conditioning of the air.

With all of that being said, we don't base top offs on how much kalk we need because of how the systems vary in evaporation. It's easy when they match up, but it becomes a pain when they don't and you have to figure out a way to dose the kalk without bottoming out your salinity.