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Reservoir temps

cecebe

New Member
The universal advice for reservoir temps is to keep them in the 60s in order to maximize dissolved oxygen. I am running 2 airstones in each container and have no chiller. Temps are about the same as room temp - mid to high 70s.
It seems to me that bubbling this large amount of air around the roots would provide plenty of O2. Perhaps there would be other issues such as algae if the temps get up in the 80s, but so far the res is clear and clean and plants are healthy.
I would like to avoid the added expense and energy draw of a chiller if possible. Also, since the DWC setup does not recirculate, the whole plumbing arrangement would have to be changed in order to cool several containers from one chiller.
Anybody have any thoughts about this?
Thanks.
 
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Bassman59

Member of the Month: Oct 2012
Your temps are going to cause issues. Bad issues imo. Root rot is just around the corner.

I had to learn the hard way.

But it's easily fixed and not too expensively (subjective).

1. Depending on how many buckets your running and how big they are, it's possible to run a very effective 1/10hp chiller for $200. Mine runs on 1.8 -2.2 amps.

2. It isnt too hard to set up plumbing at all.

As soon as I got my temps to sub 68f all my problems went away and growing became so much easier. Having a chiller is huge.

The amount of dissolved O2 that gets into the water is much higher as the temps drop. I wouldnt count on your 70's temps putting that much into the system now.
 

PrairiePoet

Active Member
The universal advice for reservoir temps is to keep them in the 60s in order to maximize dissolved oxygen. I am running 2 airstones in each container and have no chiller. Temps are about the same as room temp - mid to high 70s.
It seems to me that bubbling this large amount of air around the roots would provide plenty of O2. Perhaps there would be other issues such as algae if the temps get up in the 80s, but so far the res is clear and clean and plants are healthy.
I would like to avoid the added expense and energy draw of a chiller if possible. Also, since the DWC setup does not recirculate, the whole plumbing arrangement would have to be changed in order to cool several containers from one chiller.
Anybody have any thoughts about this?
Thanks.
If "The Universal Advice" is to keep the reservoir around 68F, then why would you think that doing anything else would be workable?

Bassman59 has it right on the button. Lower reservoir temps in a DWC is a must, not just for better oxygen dissolving, but to keep out root rot (not algea as that comes from light hitting the water).
 
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Bassman59

Member of the Month: Oct 2012
well if u got big temp problems in the reservoir u can supply the tank with ice.. use water bottles, freeze them in the freezer and drop the frozen bottles in the reservoir
You do not want to do this once roots are in the water. The ice will freeze the roots and they'll break off.

Now an alternative is to have the tub or bucket sitting inside another tub with a water bath and place ice jugs in that to cool it from the outside. But you will have to change it out often.
 

cecebe

New Member
Thanks for the help. I will start on figuring out a chiller system, probably the 1/10 hp unit. PrariePoet, the reason I thought my temps were workable is simply that they have been working, for 6 weeks. Yes, I know that doesn't necessarily make it right, but that's why I asked in the first place, just to see if there were some other ideas. There is at least one successful grower on here who doesn't chill, in a warm climate.
Again, the advice is much appreciated.
 

cecebe

New Member
No problems so far. This is a DWC bubbler with two grow tubs and a reservoir in the same closet. Lighting is 400W LED. The bedroom that the closet is in has a window AC which helps but it seems wasteful to cool a room just to cool a closet. Continuous venting through the roof. Trying to anticipate the hot days of July/Aug. Temps are in the mid 70s now.
In flower now, so the grow is staying cooler in the dark period.
The problem with cooling this system is that there is no pump to circulate between the res. and the grow tubs. The res seems to be most useful for checking levels and adding stuff, as the tubs are under a SCROG and are getting increasingly difficult to access. Other than that it just adds 1/3 more time between topping off, which isn't much use since I check every day.
I wonder how you would balance a cooling system like this - recirculating cooled nutrients from the res to two separate tanks and returning by gravity. Seems like a recipe for disaster if the pump runs even a hair too fast.
Anyway, you asked a simple question and got a long-winded answer.
 

Bassman59

Member of the Month: Oct 2012
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I wonder how you would balance a cooling system like this - recirculating cooled nutrients from the res to two separate tanks and returning by gravity. Seems like a recipe for disaster if the pump runs even a hair too fast.
Anyway, you asked a simple question and got a long-winded answer.

That's basically exactly how it's done.

I don't have any decent pics to show but post #84 in my master kush grow is about as close as possible to show.

420 Magazine ®

The line coming from the top of pic in a "T" is my pump, sucking out of the tubs and pumping through the chiller, to the main res, which gravity feeds the girls.
 

cecebe

New Member
I checked out the pics and other posts that show how you did it. Very helpful and much appreciated - thanks!
I can't do anything this time around because of drilling extra holes in the tubs, but I'll keep my fingers crossed and hopefully have pics of a successful grow that I can post. After I read the 420 how-to, never done it before.
Starting seeds now for the next grow w/ the new system
My tip 'o the day - get a step drill from Lowes, MSC, etc. Essential for drilling nice round holes in thin material without snatching, and you can size in 1/32" increments if you get the right one.
 

Bassman59

Member of the Month: Oct 2012
Hopefully, if I get it right, my next grow will use 2" pvc for everything, then 3/4" on the return side to the pump/chiller for better flow.

I messed that up the first time and didnt have enough seals to do it proper. Hence I say Hopefully. I should be able to get it right this time.
 

cecebe

New Member
Yeah, that's what I was thinking of - nice big lines on the gravity side so everything goes back as easy as possible.
My system came with black 5/8 vinyl like you would use in a garden irrigation. I didn't like it because it kinked easily. Same with the clear vinyl I got to replace it. The reinforced vinyl resists kinking but was too stiff. So I wandered in to the fish pond section in Lowes and found black 3/4" corrugated hose. It looks like vacuum cleaner hose, and is relatively smooth on the inside. Boy is that stuff nice - you can bend it any which way and it won't kink and it flexes real easy. You can move tubs around without stressing the fittings. It's a little pricey, but ...
 

StonerJ

New Member
Your temps are going to cause issues. Bad issues imo. Root rot is just around the corner.

I had to learn the hard way.

But it's easily fixed and not too expensively (subjective).

1. Depending on how many buckets your running and how big they are, it's possible to run a very effective 1/10hp chiller for $200. Mine runs on 1.8 -2.2 amps.

2. It isnt too hard to set up plumbing at all.

As soon as I got my temps to sub 68f all my problems went away and growing became so much easier. Having a chiller is huge.

The amount of dissolved O2 that gets into the water is much higher as the temps drop. I wouldnt count on your 70's temps putting that much into the system now.

I agree 100%. I struggled with temps that were fine for the plants but too high for the reservoir and over the course of the day, the reservoir temps would climb to be the same as the room (high 70's-low 80's). I finally broke down and bought a 1/10 HP chiller and I aws only using a 5 gal bucket DWC. I knew however that my next hydro grow would be considerably larger (27 gal res) so I bit the bullet and bought the chiller. Found a killer deal on an Active Aqua 1/10 HP chiller for $269 and only $18 shipping. I had it in 2 days and what a difference. No more temp worries. Just the chiller, a $16 160gph submersible pump from the hydro store along with about 8' of black 1/2" tubing and I installed the chiller outside the grow room. With a small reservoir it doesn't run that much anyway and once the temp concerns were out of the picture, my daily maintenance became much easier. pH levels were instantly more stable and nutrient solution uptake was definitely better.

And the results were absolutely worth it.
 
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