Best temperature to keep algae and slime out of your water reservoir with DWC

A question from a fellow grower:

What is the best temperature to keep algae and slime out of your water reservoir when growing in DWC.

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It is not a matter of temperature. It is a matter of keeping UV rays out of your reservoir. :slight_smile:

Yes it is more a matter of keeping all light out of the reservoir and making sure there is enough aeration. That being said, the reservoir should be kept well below 78F(78F is about the maximum temp for DWC and still keeping dissolved oxygen at a reasonable level), about 70* is ideal, to keep dissolved oxygen levels high. Too cold is obviously not good either. Never lower than 60F either, about 68F-70*F is about ideal.

Happy Growing,


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BTW, to clarify…

We are talking about the water temps and not air temps here. But if you are not letting your air temps get above ideals, and this is generally agreed to be best at about 72F to no more than 78F in hydro indoors without CO2 supplementation during lights on and during lights off not much below 68*F, and so your reservoir isn’t likely to be much above or below these temps if you are maintaining air temps.

Also, as an added bonus I hear the typical true spider mite does not like temps at 78*F or below, and this would help with preventing or slowing infestations.

Green Algae is indicating too much light is getting into the reservoir.

Brown, red, black, or grayish slime/sludge is indicating not enough dissolved oxygen in the water and so you need to add more aeration and/or get the temperature lower if it is too high.

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