Reservoir Water Temps, Low End

[CaptKilljoy]

Still planning a first grow, but in the meantime I'm doing lettuce in DWC style tubs. 3 weeks in and I'm seeing slow growth and another thread popped up about res temps, and finally it's one about maybe not being warm ENOUGH instead of the constant opposite of having way too hot.

My 8g tubs are sitting at 60F, which I'm beginning to think is too low for my lettuce - but what's "too low" for cannabis? It's 25F outside, and my grow room is in the basement that I don't keep heated except for my small home office.

Wondering now what considerations I'll need for winter grows and keeping water temp up (but not too up as to encourage root rot and negative bacterias)...

 

[Bill284]

Still planning a first grow, but in the meantime I'm doing lettuce in DWC style tubs. 3 weeks in and I'm seeing slow growth and another thread popped up about res temps, and finally it's one about maybe not being warm ENOUGH instead of the constant opposite of having way too hot.

My 8g tubs are sitting at 60F, which I'm beginning to think is too low for my lettuce - but what's "too low" for cannabis? It's 25F outside, and my grow room is in the basement that I don't keep heated except for my small home office.

Wondering now what considerations I'll need for winter grows and keeping water temp up (but not too up as to encourage root rot and negative bacterias)...

A seedling heat mat under your res tank will help.
You can get one with a stat controller and set it where ever you need. Cheep and easy.

 

[CaptKilljoy]

yeah, i'll have a number of options, just wondering if 60F demands those options. the recirculating pumps I have are in-res so hopefully that will bump up a degree or two. getting the tubs off the direct ground and on spacers will proabably help as well. i thought cold (at least for lettuce) was super good so i tried to keep them as chill as possible.

 

[Bill284]

yeah, i'll have a number of options, just wondering if 60F demands those options. the recirculating pumps I have are in-res so hopefully that will bump up a degree or two. getting the tubs off the direct ground and on spacers will proabably help as well. i thought cold (at least for lettuce) was super good so i tried to keep them as chill as possible.

If you set anything directly on the floor will automatically cool to temp of floor.
Even a 1 inch air gap will make a huge difference.

 

[CaptKilljoy]

That's the goal. Just because being low is bad for me and the wife's back (no can do on getting on knees at all). But maybe until I can build a proper shelf i need to find some stuff to just prop the tubs I have up off the ground a little...

 

[Bill284]

That's the goal. Just because being low is bad for me and the wife's back (no can do on getting on knees at all). But maybe until I can build a proper shelf i need to find some stuff to just prop the tubs I have up off the ground a

Empty will help. I have a broken vert, no lifting for me either.

 

[CaptKilljoy]

for today, i put my tubs up on 2020 (mm) aluminum rails to get them ~3/4" off the ground. will check res temps in a few hours and compare.

 

[CaptKilljoy]

Approximately 2 hours later ( yeah, not a lot of time ) - no change in res temp. So I dumped a little submersible pump in the tote. Everyone says submersible pumps tend to heat up the res when growing in a warm climate, so I'm going to test putting one in to combat cold climate. Will check in a few hours, see if we have any movement in temps. Since the pumps are free (already had them and they were given as part of another grower's lack of interest) and they're really crappy aquarium pumps, it wouldn't be a major loss if it dies. I'm not pumping any actual water anywhere, just dumping it into the bottom of the bucket and turning it on to see how well it works (or doesnt).

 

[Bill284]

Approximately 2 hours later ( yeah, not a lot of time ) - no change in res temp. So I dumped a little submersible pump in the tote. Everyone says submersible pumps tend to heat up the res when growing in a warm climate, so I'm going to test putting one in to combat cold climate. Will check in a few hours, see if we have any movement in temps. Since the pumps are free (already had them and they were given as part of another grower's lack of interest) and they're really crappy aquarium pumps, it wouldn't be a major loss if it dies. I'm not pumping any actual water anywhere, just dumping it into the bottom of the bucket and turning it on to see how well it works (or doesnt).

I have a small submersible in my little 100 liter tank if I forget to turn it off it will boil a 100 liters no problem. As long as the pump has liquid flowing it is self cooling. Put a plug in the intake and it should warm up.

 

[CaptKilljoy]

haha. plug the intake of a pump and i'll have an electrical fire.

while it's self cooling (to the pump) the heat generated does go somewhere - ie: into the water...it's a matter of how much it generates. i'm guessing this tiny pump will not be enough to change anything and i'll have to go find an aquarium heater or seed mat heater.

 

[Bigjake8]

Aquarium heater is the way to go get one thats adjustable set on 68 and go im in the same boat cold basement and concrete floor
I have ran my water down to 50f before and they get mad below 60f just what I grow anyhow some say you can go lower on water temp as long as rhe room is above 68 air temp but I don't know if its the paranoia or what but seems to me they get mad