Temperatures

Machead: I'm one of those yanks who doesn't do well with the Celcius temperature scale so you'll have to do the conversion. At school, for hydro, they recommend 65 degrees F at night to 75 F in the day time. I've pushed it to 80F without any problems but that's why I went back to dirt, it's a lot more forgiving. I hope that helps. HSA

If you add co2 you can run at 98F 36C

Increasing the atmosphereic pressure of the grow room can also help plants cope with higher heat levels.

Why would your target be the max the plants can tolerate? If you knew that and you accepted that, you would get a crappy yield. If your goal is to keep plants barely alive, that's what you'll have - barely alive plants, not worth the effort.

You should worry more about water temperature

Originally Posted by Illegal Smile

Why would your target be the max the plants can tolerate? If you knew that and you accepted that, you would get a crappy yield. If your goal is to keep plants barely alive, that's what you'll have - barely alive plants, not worth the effort.

You must read my message wrong i am not trying to attempt to keep them barely alive the outside temps are prob the hottest they been in the UK for years. an i am struggling to keep the temps in the room down.

Just wanted to know what the max was.

Thanks for the CO2 comment i do have that in the room so it should be just fine.

Originally Posted by machead

You must read my message wrong i am not trying to attempt to keep them barely alive the outside temps are prob the hottest they been in the UK for years. an i am struggling to keep the temps in the room down.

Just wanted to know what the max was.

Thanks for the CO2 comment i do have that in the room so it should be just fine.

Air temp is a lot less important than your res. temp.. Just keep room as cool as you can and keep the res. temps around 60to65f.. The cool res temps will help them deal with the higher air temps..