Sativajoe said:

Hey farmers,
I'm having a go at dwc, but and struggling with water temperatures,, I keep creeping up to about 23 degrees Celsius,, is that too warm,

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It's certainly getting toward that borderline, but I think your still OK. Some of the others with better experience can probably answer this one.

Sorry I use F, yet my temps averaged 72.5 for veg, and 73.5 for flower. During the last few weeks when my lights were max, my water temps were around 74.5.

This high temps will make fungi grow on your roots (faster than usual) inside your reservoir. If you are trying to run a sterile environment I would add a chiller, which isnt feasible for a dwc. I would say you need "Hydroguard" or a similar additive with bacteria that will help combat the root rot.

Your main problem with high temps will be brown slimy roots, or black patches in your roots. Hydroguard isnt as good at eliminating it as it is preventing it. If you have root rot already, massage the roots with your hands gently until you feel the slime gone. Then change your res, and add a double dose of hydroguard. Repeat res changes until roots are not slimy for 48hrs, then back down to regular hydroguard dose.


For the record, since your doing dwc, if you want to try something new, or look into it, Im pretty sure you can drill a hole in the top of your netpot, and inline a small pump, just mount it to the side of the pot. This has nothing to do with water temps though, more less increased growth rates and more stable ppm and ph throughout. Just something to look into if your limited on space.

Props on the hydro grow, good luck, we will be here!

I have been growing dwc for about 10 years, and i just had my first root-rot. The root-rot appeared after about 1 day of 23-24 celcius.
I usually keep the temperature under 21 celsius. But now, the summers where i live, has become warmer and it is becoming harder to keep the temps down.
I tried to cut the damaged roots off, and was hoping for a rebound. But this did not happen.

So after a complete sanitation and new air-stones, i started over again. Now, i am freezing 1.5 liter bottles with water, and putting them into the reservoir (with the roots), when the temp exeed 21 degrees celsius.

Young plants are more susceptible to root-rot. So now i use canna rhizotonic, the first 2-3 weeks. It really helps to form white healthy roots.

I usually have problems with high water temps in the beginning of each grow. This is because the light are closer to the reservoir. I also cover the black 70 liter reservoir with white A4 paper, so that the light energy is reflected instead of warming the reservoir.

Good luck to you