DWC to RDWC conversion

[marzig]

I'm planning on possibly upgrading my DWC system to recirculating when my current grow is finished and have a few questions.

I'd like to reuse anything I have now if possible. I have a cooler I want to use as the reservoir. Are there any pros or cons to having an insulated reservoir?

I'll be buying a chiller and my next question involves changing the nutes. The fresh solution will be warm so does it go into the res and then pumped through the chiller and then into the buckets? Will the chiller be able to bring the temp down the from say 74 to 67 to not shock the roots?

I want and can afford to buy a good quality chiller. Any recommendations for brands and size for a 30 gal two bucket system?

I appreciate any advice and comments.

 

[Delps8]

I'm planning on possibly upgrading my DWC system to recirculating when my current grow is finished and have a few questions.

Congrats. Having the additional volume will take a little more work but I believe it's worth it. I grow in a DWC sytem but it's a large res that holds 26 gallons of nutes so it's got the additional volume of nutes that you'll have.

I'd like to reuse anything I have now if possible. I have a cooler I want to use as the reservoir. Are there any pros or cons to having an insulated reservoir?

Per the picture above, my res is just a fiberglass tub and it's not insulated. I've thought about adding insulation and chosen not to because having a "big bucket" of cold water helps keep temps down and, in my environment (a garage in Southern California) it's better to have a cooler temp in the tent that allowing heat to build up.

The big driver for that is to keep the tops of the flowers <=78°F. According to Mitch Westmoreland, PhD student under Bruce Bugbee, that's the highest you want to have your flower tops after week 2 of flower. He mentioned that in a YTY video about three years ago and released two videos this year in which he shared the results of his research (I highly recommend them).

But that's what works in my setup because it tends to be warm/hot. If you're in a cool environment, you might want to add insulation.

I'll be buying a chiller and my next question involves changing the nutes. The fresh solution will be warm so does it go into the res and then pumped through the chiller and then into the buckets? Will the chiller be able to bring the temp down the from say 74 to 67 to not shock the roots?

Not an issue. Roots are very hardy - "shock" isn't something that I'd think you could do to a root. It's designed to anchor a plant so, even though they're porous, they're also fibrous and very strong.

My nutes go in the res at, say, 75° or maybe a little higher and res temp is down to 68° in 4 or 5 hours. The manual for your chiller should have a graph that illustrates the cooling values of the chiller.

Since there's a lot of water involved, I use two 25' flex style hoses and a 330 GPH Trupow sump pump. It takes about 5 minutes to empty the 16 gallon res. I mix nutes in a plastic 32 gallon "Brute" trash can, using a canoe paddle to stir the nutes. I use Jacks 3-2-1 which is a dry fert.

I want and can afford to buy a good quality chiller. Any recommendations for brands and size for a 30 gal two bucket system?

I appreciate any advice and comments.

My res holds 26 gallons and I have a 1/10 hp Active Aqua chiller. I bought it in 2017, used if for one grow and archived everything, and then have used it for at least half a dozen grows since early 2021. I've had no issues and would buy the same model it this one failed.

I'd be interested learning about your setup. I'm toying with the idea of getting a system from PA Hydro, two 13 gallon buckets plus an external 13 gallon bucket.

 

[marzig]

Congrats. Having the additional volume will take a little more work but I believe it's worth it. I grow in a DWC sytem but it's a large res that holds 26 gallons of nutes so it's got the additional volume of nutes that you'll have.

View attachment 5412794


Per the picture above, my res is just a fiberglass tub and it's not insulated. I've thought about adding insulation and chosen not to because having a "big bucket" of cold water helps keep temps down and, in my environment (a garage in Southern California) it's better to have a cooler temp in the tent that allowing heat to build up.

The big driver for that is to keep the tops of the flowers <=78°F. According to Mitch Westmoreland, PhD student under Bruce Bugbee, that's the highest you want to have your flower tops after week 2 of flower. He mentioned that in a YTY video about three years ago and released two videos this year in which he shared the results of his research (I highly recommend them).

But that's what works in my setup because it tends to be warm/hot. If you're in a cool environment, you might want to add insulation.


Not an issue. Roots are very hardy - "shock" isn't something that I'd think you could do to a root. It's designed to anchor a plant so, even though they're porous, they're also fibrous and very strong.

My nutes go in the res at, say, 75° or maybe a little higher and res temp is down to 68° in 4 or 5 hours. The manual for your chiller should have a graph that illustrates the cooling values of the chiller.

Since there's a lot of water involved, I use two 25' flex style hoses and a 330 GPH Trupow sump pump. It takes about 5 minutes to empty the 16 gallon res. I mix nutes in a plastic 32 gallon "Brute" trash can, using a canoe paddle to stir the nutes. I use Jacks 3-2-1 which is a dry fert.



My res holds 26 gallons and I have a 1/10 hp Active Aqua chiller. I bought it in 2017, used if for one grow and archived everything, and then have used it for at least half a dozen grows since early 2021. I've had no issues and would buy the same model it this one failed.

I'd be interested learning about your setup. I'm toying with the idea of getting a system from PA Hydro, two 13 gallon buckets plus an external 13 gallon bucket.

Thanks for your reply!

I have a 2x4 tent shoe horned into my small bedroom closet.


I'm using 2 Hydrobuckets that hold 4 gallons to the bottom of the root plug. These are the only reason I got into DWC. With the the side reservoirs it's never necessary to lift the plants up to do maintenance and roots can easily be inspected.


They also allow me to rotate the plants and attach trellises. I have them sitting in a large cooler in water and a heat exchange coil to cool them. This large cooler will be removed when I switch to RDWC.


Outside of the tent, I have a smaller cooler with frozen jugs of water and a pump that circulates the chilled water through the coil in the cooler inside the tent. This pump is controlled by a thermostat with it's sensor located in the water bath that the 2 Hydrobuckets sit in. Kind of a "Rube Goldberg" setup but it maintains very steady nute temps and I only have to change ice jugs twice a day.


I plan on repurposing this cooler for my reservoir and placing the chiller on a shelf above. I'm a little concerned about the heat produced by the chiller but my tent always runs a little cool until I get my lights cranked up. I have a 6 inch duct fan venting the tent through the attic to a roof vent so I think I'll be ok.

If my calculations are correct, it should hold about 12 gallons bringing my total capacity up to 20 gallons. I'd like to have the capacity a little larger but I'm pretty much limited by my closet foot print.

 

[Mumbeltypeg]

I'm planning on possibly upgrading my DWC system to recirculating when my current grow is finished and have a few questions.

I'd like to reuse anything I have now if possible. I have a cooler I want to use as the reservoir. Are there any pros or cons to having an insulated reservoir?

I'll be buying a chiller and my next question involves changing the nutes. The fresh solution will be warm so does it go into the res and then pumped through the chiller and then into the buckets? Will the chiller be able to bring the temp down the from say 74 to 67 to not shock the roots?

I want and can afford to buy a good quality chiller. Any recommendations for brands and size for a 30 gal two bucket system?

I appreciate any advice and comments.

Insulated res is good if you have the space for it.. you generally just have the chiller drawing and emptying into the res, not direct to the buckets, they don’t flow that fast.

 

[marzig]

Insulated res is good if you have the space for it.. you generally just have the chiller drawing and emptying into the res, not direct to the buckets, they don’t flow that fast.

Thanks, that makes sense after thinking about. So I'll need 2 pumps then, one to circulate to the chiller and the other to the buckets.

Would I be correct in thinking they don't need to be the same size?

 

[driver77]

Here's the chiller I bought awhile back. Works great...I run from 68f to 73f but you can set it wherever you want.
chiller
You'll want the chiller outside the tent if possible.....puts out a fair amount of heat when it's running.

 

[Mumbeltypeg]

Thanks, that makes sense after thinking about. So I'll need 2 pumps then, one to circulate to the chiller and the other to the buckets.

Would I be correct in thinking they don't need to be the same size?

Yeah I just use the smallest pump available for my chiller.. just has to trickle through really

 

[Mumbeltypeg]

Yeah I just use the smallest pump available for my chiller.. just has to trickle through really

It’s a pretty hefty outlay for a two pot system.. sure you wouldn’t be better just running Bennies in there?

 

[marzig]

It’s a pretty hefty outlay for a two pot system.. sure you wouldn’t be better just running Bennies in there?

Too late now, already got the chiller in today lol. Money isn't an issue. I'm single and retired. I don't drink, no motorcycles, boats etc. Growing for me is a hobby and entertainment that I really enjoy.

 

[Mumbeltypeg]

Too late now, already got the chiller in today lol. Money isn't an issue. I'm single and retired. I don't drink, no motorcycles, boats etc. Growing for me is a hobby and entertainment that I really enjoy.

I hear you..

 

[Mumbeltypeg]

Too late now, already got the chiller in today lol. Money isn't an issue. I'm single and retired. I don't drink, no motorcycles, boats etc. Growing for me is a hobby and entertainment that I really enjoy.

I like the water bath chiller you came up with.. I like seeing a bit of ingenuity being put to use when constructing a grow room. What size light are you running with? Just talking shop

 

[marzig]

I like the water bath chiller you came up with.. I like seeing a bit of ingenuity being put to use when constructing a grow room. What size light are you running with? Just talking shop

Thanks, I appreciate that. I enjoy problem solving particularly with outside of the box solutions. The water bath chiller works well and could be adapted for RDWC, I simply lack the necessary space in my closet.

I'm using 3 of the Mars ts-1000. Down the road I'm thinking of upgrading, but I like the ability to adjust them to an uneven canopy.


I'm hoping with my new trellises and training I can level out the canopy. If successful, I'll upgrade to a higher quality single light. If not, I may look into building my own lights. Sativas really help in keeping the creative juices flowing

 

[Mumbeltypeg]

Thanks, I appreciate that. I enjoy problem solving particularly with outside of the box solutions. The water bath chiller works well and could be adapted for RDWC, I simply lack the necessary space in my closet.

I'm using 3 of the Mars ts-1000. Down the road I'm thinking of upgrading, but I like the ability to adjust them to an uneven canopy.
View attachment 5413773

I'm hoping with my new trellises and training I can level out the canopy. If successful, I'll upgrade to a higher quality single light. If not, I may look into building my own lights. Sativas really help in keeping the creative juices flowing

Looking good bud.. nice sativas, I’m too impatient for them myself 10 week flower max for me.. for the moment anyhow

 

[Mumbeltypeg]

Thanks, I appreciate that. I enjoy problem solving particularly with outside of the box solutions. The water bath chiller works well and could be adapted for RDWC, I simply lack the necessary space in my closet.

I'm using 3 of the Mars ts-1000. Down the road I'm thinking of upgrading, but I like the ability to adjust them to an uneven canopy.
View attachment 5413773

I'm hoping with my new trellises and training I can level out the canopy. If successful, I'll upgrade to a higher quality single light. If not, I may look into building my own lights. Sativas really help in keeping the creative juices flowing

Learning to build them would be a worthwhile project I recon.. I have started looking into it before, one day perhaps. I went straight for the bigger Bar lights but have thought a few times since that multiple small ones may have been a better option with more flexibility in canopy control.. so long as they are still getting enough light delivered..the rest is just wank and marketing

 

[marzig]

Insulated res is good if you have the space for it.. you generally just have the chiller drawing and emptying into the res, not direct to the buckets, they don’t flow that fast.

I'm going to be draining my two buckets through 2" pvc in a short, straight line to my res. Do you think this will be adequate to keep up with the flow directly from the chiller through 3/4" lines?

 

[Mumbeltypeg]

I'm going to be draining my two buckets through 2" pvc in a short, straight line to my res. Do you think this will be adequate to keep up with the flow directly from the chiller through 3/4" lines?

I have seen setups with a chiller in the return line now that you mention it, if it can handle chilling with that kind of flow I don’t see why not.. I see that undercurrent set ups often chuck an inline filter in the return line before chillers/pumps.. might be a bit of peace of mind.

 

[Mumbeltypeg]

I have seen setups with a chiller in the return line now that you mention it, if it can handle chilling with that kind of flow I don’t see why not.. I see that undercurrent set ups often chuck an inline filter in the return line before chillers/pumps.. might be a bit of peace of mind.

Something like this..

 

[Mumbeltypeg]

Again.. might be overkill for two pots, but I like to overengineer

 

[Drop That Sound]

Here is the best and still the most affordable Y-strainer on the market for RDWC\undercurrent systems with 2" manifolds, IMO.

 

[marzig]

Again.. might be overkill for two pots, but I like to overengineer

I'm starting to wonder now if my idea will even work. I think maybe it's a hybrid system, not a true undercurrent. I plan on draining from near the bottom of the buckets into the bottom of the res. Then pump from the res through the chiller and then waterfall into each bucket.

My thought is that since the buckets and res are on the same level pumping from the res to the top of each bucket will create a current or flow through the system.

Do I have this all wrong?