water heat good or bad?

I have been using bottom heat for sometime on seedlings and sensitive plants. Last season I heard a lot about heated water being bad in hydroponics systems? I am not sure why does it cause a lack of oxygen? If so what is the desired heat and how are most keeping the water at this temperature?

Once your water gets past 80°F, there is little oxygen available to the plant and you are also creating a very hospitable environment for the bad stuff to grow. Past 85 degrees and the roots suffer. There are three options to cool your water. Get a bigger tank. The more water, the smaller temperature variation you will have. Bury your tank. The ground is a natural insulator. See my post “pole beans” or get a chiller
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