[BCReefer]

for the best optimum growing conditions the TDS and pH, like our aquariums, must be in a certain range. They also look at the oxygen on water and water temperature. If you need a cheap (or less expensive) chiller check out your local hydroponic store. They also have great lighting control devices and devices to continuous measure the pH and TDS. Check out some of their sites and you can see what they have.

Happy growing ..... oops meant happy aquarium keeping.

Cheers
Patrick