Ideal location for Calcium Dispenser output?


New member
I just purchased the Osmolator 3155, Calcium Dispenser 5074 and 7 gal. Container 5002.25 for my 55 gal. reef with 29 gal. sump.

I have followed the threads here closely, which is what actually led me to this purchase. I think it's going to work out well for my setup.

My question is - should the output from the calcium dispenser go into my sump or directly into the main tank, say in the area of my main return so it mixes thoroughly? I know the drawback of returning it to the sump is that eventually my pumps will suffer from a calcium buildup and could burn out.

What do you recommend? Also, is 4 tsp. of kalk for the 7 gallon container a good starting point in terms dosing a tank of this size?

Thanks! This forum has been very informative.
Unless your sump is above the top level of the reservoir it needs to go to the tank. Remember, the pump will start a siphon if it is pumping to an area below the reservoir, then after the pump is turned off the entire reservoir can siphon into your sump. Water always has to be pumped up hill. I would start with 2 tsps and make sure the tank is topped off before you add the powder and follow the directions regarding adding the powder. It should work well for you but being a smaller aquarium you have to be more careful as a little kalk powder can drastically influence pH. I think 4 tsps is a bit much for this size aquarium and could influence pH more than I would like.