Salt water mixing question - heating up

[bucfan]

I have a mixing station set up in my garage with an external pump hooked to a barrel to circulate the water. I put RO water in the barrel and salt mix then start the pump and run it to mix the salt up. The problem I notice is that after running the pump for a few hours to get the water completely mixed the temp is up to 90 degrees or higher. That causes two problems. Some of the mix precipitates out and the alk is low. Also the water is unusable until I can get the temp down. So how do I prevent this from happening. I used to have a sump pump inside the barrel which would nearly boil the water. Thought moving to an external pump would solve my problem. But it seems the water still gets hot. Any ideas? Could I be mixing too long?

 

[Shadow1]

What is the temp in the garage? Florida is warm this time of year.

 

[bucfan]

Temp is prob around 95-100. However my RO water which is not circulating and sits in a similar drum by the salt mix is at 80-82. So the only thing that explains the heat is the pump.

 

[chemisfun11]

Most salts are more soluble as water heats up. If you have calcium in your RO water (district water/well water typically have calcium dissolved in it) that could be precipitating out as your temperature increases. As far as your temperature issue goes, I'm surprised that the external pump is adding that much heat to the water, but you may want to manually mix the water (a pain I know, but if you add salt slowly as the bucket fills, it should help) or you could add a fan for evaporative cooling, or try a different external pump. Hope this gives you some ideas.

 

[bucfan]

I have a Pan World P50X pump. Does that generate too much heat?

 

[Reefing Madness]

I just use a powerhead to mix my salt up. Why do you need such a powerful pump to do it? Powerhead= less heat and less power to run.