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Is DWC doable in summer without a cooler?


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Hey guys and girls, long time no see!


I'll get to updating my other grows that have been abandoned for a few months but have since finished with varying success.

Before starting another diary that will likely end in doom...


I started a DWC about 6 weeks ago but have been battling water temps since the start and that has brought all kinds of problems with ranging from clear slime, brown slime, urine smells and stunted growth that it all caused.

I have had to trim my roots back to near the bottom of the pot 3 times now to get rid of the mentioned slime.


I was doing ok in a small bucket(5L) till about 3 weeks ago when i decided to step it up to a massive(nearly 50L) wheelie bin from Crazy Clarks. I was in there just "looking" when these things slapped me in the face and at just $15 each, i snapped up a pair of black ones with DWC in mind.


Anyway, my question is..

Is anybody having great success in the summer months without cooling their water?


My highest water temps are around 25c which i read is on the high side for DWC.

I have considered using frozen bottles but currently i am not using a reservoir so i am assuming that putting frozen bottles in the wheelie bin could cause problems with the root zone?

Option 1 would be to somehow attach the frozen bottles to the outside of the reservoir using cloths and duct tape.

Option 2 is to plumb a reservoir in and cool the res with frozen bottles.

Option 3 would be to buy a cheap, used water cooler and somehow attach it to a reservoir.


FYI, i am assuming i have enough airflow though my tent and i also think i have an acceptable amount of air getting to the root zone. I am using a four 5 x 1cm air stones running off a 9lpm air pump with 4 outlets.


If it helps, my nutrient are 1ml per liter for all the following...

Canna Aqua A & B

Cal Mag




Plus H202


At one stage i used some Bacillius thuringienusis strain 14 instead of the H202 to get some good bacteria in the res instead of attempting to kill all bacteria. It was fairly successful for a few days for getting rid of the slime and i have not seen and fungas gnat since then(there were couple in the root zone at one stage) but i just cant' seem to get on top of it all.


Seriously considering changing my name to Problem Guy! lol

It seems the only time i report anything, it is disaster :(


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I have grown DWC through summer a number of times no worries, as you know you will have to do something to maintain cool water temps.


If you're set on using ice consider cooling the air you are pumping into the water. I haven't tried it myself but I believe it would be sufficient for dropping the temp a few degrees if done well.


Good luck.


Naycha :peace:

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Thanks for the advice guys, always appreciated :)


RE: H202 + Cannazyme

They were not used at the same time. The H202 was used initially at a lowish dose and then 4 days later i noticed a lot of dead root matter in the res so i added the cannazyme in an attempt to clean it up a bit. Seemed to work ok but the slime is nothing to be take lightly it seems.

So yeah, they were both in there at the same time but from what i read(which can be dangerous in its self) the majority of the H202 would have disapated?


I have logged a lot of what has happened with some quality photo's.

Last night i was just about to start a new grow diary thinking i was on the right path with the slime. I figured i would check it one last time before posting so i did not jinx myself. I was not too surprised to find more slime starting to form on the roots.

So i have ditched the wheelie bin and gone back to a 5L bucket and i am currently washing the roots with a fairly heavily dosed H202, PH'd water. The roots are clearing up again but i am reluctant to go back to the wheelie bins till i have a solution for temps as wasting 35L of nutes multiple timer per week is getting a bit old :(


I don't care if i am not able to flower under a HPS in summer as long as i can veg under a CFL.

I don't think my temps are too far off being safe but i really need to do something about them.


EDIT: Currently eying Gumtree for a $50 bar fridge or water cooler.

Edited by Caffeine
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I've been in a very similar situation. I had huge temp issues with DWC through summer. I was packing ice bricks around my res, sitting ice bricks under the res, towels around my grow box. They worked to an extent, but it was just more work..and all of the proper solutions I found were expensive (air/water conditioners).


ended up just switching to coco..

Edited by Artifice
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OK! Quick update...


My DWC has gone through a few incarnations so far. I opted not to use the wheelie bins for now but will deffinately revisit them in the future. For now i am using a modyfied beer fermenter with a tap on the bottom. I painted around the top and bottom with matt black paint and covered the mid section with reflective matirial. The main reason for this is to reduce the amount of nutirents used(roughly half).


I have not used a HPS all sumer, instead i am using a 130w CFL. Temps were rarely +2 more than ambient temps so all good there.


My root problems have pretty much cleared up.

I have cut back all roots a couple of time already and by running H202 all the way through the grow, i have eliminated any slimes and nast smells.

My only problem now is that the roots always seem to get to around 10cm from the botom of the net pot and then they slowly turn brown and sorta dry up. I am putting this down to the containers i have had them in not having enough room in the botom for the roots and that they were damaged from constant contact with either the side of the those buckets, the air lines or even the air stones.


So yeah.... goin ok i guess. I am going away to Melbourne next week for the F1 GP so i guess that will be the biggest test for the new system.

I am getting sick o f relying on other people to look after my tent while i am away due to me always coming home to some sort of problem so i elected not to do that this time. If i come home to dead plants then i will just start over....again lol.

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