water temps compared to air temps

just set up my rdwc, i have a temp reader that has a flying lead so it gives you 2 different temp read outs.

got it all up and running and i find my air temp is around 69, but the water temps are around 74 which seems odd or is it normal that the water would be higher than the air?

i know the water temp is a bit high so i will have to rap all the tubs in mylar i guess to reflect the heat a little bit

try reflectix , it's a shiney bubble wrap that will insulate it much better than a mylar sheet. just cut it out and tape it, packaging tape will work

did it go up or did you put the water into the reservoir at that temperature?

is the lid black?
make sure your air pump is in front of the intake or somewhere cooler than the rest of the room
and is that your peak day temperature??

thanks for the quick reply nizza

it rose from 64
yes the lids are back on
my air pump is next to a fan, but tbf i never really thought about it might need cold air so it doesnt pump warm air into the water. I think i will move the pump outside the tent.
no its not really peak time

Its the pump warming the water. Are you using a timer?

i have now moved the pump outside the tent just incase it was warm air being pushed through as today it hit 83.

i am not using a timer on the pumps, tbh didnt know you was ment to. I have just been reading up on this and most people saying dont, the odd one or 2 are saying they do because of iron defectiveness????

Its not the air pump, its then water pump. They put out a ton of heat and if running a true rdwc you will need a chiller. That's the big drawback, in my aero/nft systems my temps never go above 70 and I don't use a chiller.

Hey super are you sure about your temp? Is 70 degrees your room temperature? Only thing I can think of is your reservoir is sitting on concrete and in a different room? If your reservoir is located in your grow room it will be dictated by your room temperature.

Correct see to your pumps and wonder why they are so hot?

I try to keep my res. at 63-66.
I run dual air stones 24/7 in my 25 gallon res. It is insulated and I still see my cooling pump kick on at least twice during a lights on cycle. I keep my room running 78 during lights on at the hottest. I start dropping my temps at 6 weeks into flower and finish them at 65 lights on. Even at a 65* room temp down to 58 lights out. I still see the cooling pump fire up after the light fires up for a few hours. I have let it go and it went as high as 73 before I plugged the pump back in, so I was convinced it would have gone to an unsafe level without a touch of cooling now and again.
I think a cooler res is a healthier res.

Peace and Great Grows

Asmallvoice

hammer21 said:

Hey super are you sure about your temp? Is 70 degrees your room temperature? Only thing I can think of is your reservoir is sitting on concrete and in a different room? If your reservoir is located in your grow room it will be dictated by your room temperature.

Click to expand...

,
I said my res temp, that is what we mare talking here. Another positive for larger res, 50gal makes many things easier. My res does sit on concrete but is also well insulated. My room is 66 off and 84 on, the res's will stay between 67 and 70.5, just because broom readings at canopy level say 84 doesn't mean it is that temp at floor, even with multiple fans.

Just buy a chiller. Instead all this guessing work!

Spec with DWC if don't need it now u will in the summer

well i moved the water pump outside the tent but the water still is high. My res is outside the tent which is lower but the buckets inside are still getting to hot around 79. Just seems weird that the air temp is around 68 but the buckets are around 80 but when you put your hand in the water it feels colder than room temp.
My buckets are black though which doesnt help.

does wrapping them in mylar help keep them cool? or is a chiller the only way? just seems weird because i live in a very cold area

insulate the buckets and lines. and you could get "cool coils"
i was thinking of an alternative to cool coils, possibly a small size of expandable PEX, run through a ground loop

my basement is all dug up and set for a french drain because cracks in the foundation (poured in the winter...)
i could just dig down, and coil some pex underneath, ground temp is always ~60 degrees.
the coil would act almost like a geothermal setup, for cooling

alls it would take to run it is a circulator with proper head (75$) and pex +fittings and electrical stuff (prolly 60$) and prolly a heat controller ($?)


inline pumps are preferred over submersibles so that they can be air cooled instead of the heat pouring into your water.

instead of doing a ground loop like a said you could do it with an icemaker or something into a reservoir with an overflow and a circulator

Unnless you used a proper pipe, pex just doesn't conduct enough heat to do that, it would not work.

good to know; the reason i got this idea was from radiant floor heating loops they do with just pex; i figure the idea would apply here too

but like you were saying, much more heat transfer effective using copper as the ground loop and stainless as the res loop, with pex or whatever inbetween

i totally agree with all the other posts though, i just love concepts and creating ideas; most ideas aren't under KISS guidelines though

do it right the first time fixing the problem and that will be the end of it

Here is a shot of my cooling coil in a 25 gallon res. It is 1/2" stainless tubing and I run a glycol mix through it. that is setting in the freezer just outside the room. I can go from 75* water to 63-65* in about an hour, sometimes a bit more. I have enough 1/2" sch. 40 stainless pipe to fabricate another that has many more times the surface area and should prove to work more efficiently.


Peace and Great Grows

Asmallvoice

nice asmallvoice how much did that set you back?