How to automatic mixing water

[sphelps]

Originally Posted by golf nut

Would a double stage cylinder be a better choice if it could be produced inexpensively?what volume would you need to move?

Not sure what you mean, can you explain? There is of course is a ton of different methods to remove and replace a consistent amount of water, I just mentioned one that I've used before.

[donlite]

In the end all I used was 2 aqua lift pumps and a 30 gallon tank from coke. The salinity is dead on. They turn on for a few minutes every hour and thats it. I have to use 2 pumps because if I drain first the 3rd aqua lift pump (for water top off, fresh water) will start up.It works very well but make sure the tubes do not fall out of the tank. I water top offed my floor for about 2 hours