Grow Mediums Water Temps

[Cave Toad]

I am getting ready to start my first DWC grow using a bubbletronics hybrid system. I am going to be using 6 - 5 gallon bucket connected with an underflow' 5 for plants and 1 for reservoir. All buckets will have air stones and there will be a water pump in the reservoir to put top flow into each of the 5 net pot bases. I will have good circulation and aeration that way. I am still concerned with the possibility of root rot however because unless i add reservoir cooling my water is still likely to run in the 75 deg range. That will also reduce o2 capacity in the water as well as water and nutrient uptake, none of that is good either. Not a fan of slow plant growth.

Have any of you run into problems due to water temps and what solutions have you seen to address it? I have found a few on line but have not heard anything on how well they work.

Thanks

 

[woody]

@Cave Toad hey dude ive never ran rdwc but loads of grows in recirculated drip hydro and a few dwc single bucket grows.
My dwc grows in the summer res temps were in mid 20s for weeks. I used a product called sm90 at 0.5ml per litre. Its the only thing that saved me from root rot.

 

[Cave Toad]

@sanguine Thanks, I have heard of sm90, I checked into it it looked as though it was going to be really expensive for me, I am going to be running about 115 liters in total, but I miss read it and thought I was going to need 1:5 which was going to REALLY expensive. I see now that 2-3 ml per gallon it's far cheaper than I thought. I may go that route and if I can keep the solution at 20 or below stay with it and if not add a chiller. Even with nothing on I am at about 22.5 in the tent so not very hopeful. I do think that even if I do add the chilller I may add a little sm90 as insurance in case I have trouble with the chiller.

 

[woody]

What size of chiller does it take to keep 100 odd litres chilled?
Im sure they cost a few quid mate

 

[KushNFT]

I occasionally put bottles of frozen water in my res to lower temps if I can't do it by topping up the res. Does that work in RDWC?

 

[Cave Toad]

I am thinking a 1/10 hp will be enough, I only need to drop the water maybe 2-3 C. big thing is I think I will need to add a bit more re-circulation, my drippers are only around 8 liters per hour times 5 drippers so only about 40 liters per hour total, the reservoir will stay good and cool but the plant buckets may get warm. Probably need to add an additional small pump just to circulate water in the buckets themselves back to the reservoir.

@KushNFT I thought about the frozen bottles too but I don't think it will work very well for this since the water volume is so high and I am away too much to baby sit it. Between water changes pretty much the only daily maintenance I want to have is checking water and equipment daily and regular cleaning.

 

[Muddy]

What size of chiller does it take to keep 100 odd litres chilled?
Im sure they cost a few quid mate

A 1/10 hp will be plenty. That's all I use on a 50 gallon RDWC system and it has no problem keeping my water at 67-68 degrees even when lights on temps reach 84. To me a chiller is a must have and worth the $250 or so. I also like having the ability to drop the temp down to 62 the last week or so, tricking the plants into thinking the season is ending and promoting final ripening.

 

[kkeniff]

62-68...thats prime time for uptake

 

[Cave Toad]

I think I am going to breakdown and buy a chiller, my water temp is running at about 73 deg so it would be manageable with some SM-90 for the Root Rot protection but the o2 saturation would stay lower than I would like. One place where More's law works, more is better. Tent stays about 75 -78 right now but I only have 1 P900 LED running right now, a second will be going in later this week and then in 2-3 weeks they will both cranked up for Blooming.

 

[Muddy]

You won't regret it. Another benefit, if something goes south you can immediately eliminate temps as a cause. They do generate some heat, so factor that into your planning. For my veg room I put it outside the room and ran the hoses through the wall. It's a small room and the heat from the chiller would have been an issue given how I vent my veg room.