DIY Cooler RDWC Rig

This method is for a single 5gal DWC unit that runs on a ~600GPH pump, although you can do this for any reasonable size container and smaller pump.



Many other examples of great DWC already exist, but since I was having problems with heat in the reservoirs, and decided to rebuild using coolers, I thought to share my build with the crowd.

After discussing cooling, it was decided that the cheapest and good enough method was to just add ice packs, but to increase the efficiency of the cooling packs, so that they could just be exchanged on a daily basis, I decided to purchase some used coolers for cheap.


I started by using a 1½ “ bulkhead. You don’t need to start with ~any bulkhead if the cooler has a drain. You don’t need to use the same kind of bulkhead either.


(threaded bulkhead)

(cheaper bulkhead)

Might be cheaper to use the inexpensive units, but the threaded ones are what I have at hand, and there's perks (shown later on).

The connections were wrapped in teflon tape and stuck together (teflon not shown).

The most expensive part of any DWC I think is the pump. I don’t know if you need such a powerful pump as the one I’ve used, but I think it is best to use an amphibious pump.

Using an external pump (as shown) allows the heat of the pump to stay out of the reservoir, which is the point of using coolers in the first place.

I should have taken more pictures for the next part, but didn’t. I drilled out a 1½“ hole out of the cooler. Measure the length from the inside first and leave space for the bulkhead to bolt on inside, then measure the same distance outside the cooler and mark before you drill.

Also, I applied some silicone to the inside of drilled hole along its sides, just a prevention. I also put a bit of silicone on outside wall of the cooler where the bulkhead fits to prevent leaks.

One good thing using the threaded bulkhead is that I could use and ¾ “ male-male adapter to directly connect the pump. I used an adapter like this:



These threads are damaged so I tossed it out; I don’t need leaks.

I also decided to use a similar ¾“ adapter at the pump’s exit spout. This made it easy for me to add a quick connect adapter I got off ebay.



The yellow adapter ties into a ½“ hydrofarm line (the black stuff) no problem (nor extra parts). The gray end just screws into the ¾“ adapter. I think regular ½“ garden hose will work just as well.

So far it should look like this:



Now let’s talk about the intake. I used a hydrofarm ½“ elbow adapter and drilled the appropriate hole in the upper wall of the cooler. I then placed a ½” grommet into the inner wall of the cooler. The elbow should be pointing downwards into the cooler.

• You should fill the reservoir with 5gal (or whatever amount u planned to use) in the cooler and mark where you want the intake. You want to make a waterfall effect, so its got to be higher up that the water is!

At the other end, I attached another elbow to ~1½“ long piece of hydrofarm tubing and carefully attached it to the (cooler attached) elbow. I then filled the cavity with silicone.


The evil of used goods; ugly remnants that I should have scrubbed off… whatever.



Couple side notes

• drill the bulkhead and the intake holes on the same day and use silicone and let it dry for a day.
  
• boil some water and dip the tip of the hydroline into the hot water before attempting to push it over the elbow(s).

Now the only thing left is to attach the pump out-line to the elbow and you’re done. To unhook and drain, have another hose with a similar quick connect on it, and just switch it to the pump. Turn on the pump and it will drain to where ever you want.

Oh yea, the cover, that hoagly thing lol.

The cover is easy enough. I just used a 2” hole saw and cut right through the middle. I also added a couple smaller holes in the inside of the cover just to let water drain out instead of letting it get trapped in between. You can make a bigger hole if you plan on using larger netting cups, but 2” should cover it for this rig.

(top view of rig and an ice pack)

Potential problems

• the ice pack, I may make something to keep it in one place inside the container instead of it floating around. I should also add that this rig can be expanded on, which it will be when I stuff the plant under a scrog trellis. It won’t matter then about the ice pack as it will be in an adjoining reservoir.
• I am concerned about the pumps power and the plant’s roots getting sucked up. I will probably add another adapter inside the container (into the threaded bulkhead) that will allow me to add some aquarium filter to obstruct roots.

The unit fits good inside a tent



You may have noticed that I did not add any holes for an air pump. I don’t think it will need it.




Please feel free leave your comments and critical feedback.
Hope this post helps others.

 

I am probably going to order some smaller pumps to try them out since I'm worried about the suction when the roots get larger, and that thing is going kind hard.
Might be better to place the netting hole as far as I can from the pump end. I'm just using what I have on hand, and although I have smaller pumps, they aren't amphibious nor do they bolt up to the bulkhead.
I'd like to add that just adding cheap 3v pumps with 6mm tubing could just be all u need. Some cheap thing like this

As well, one could just use grommets instead of using a bulkhead...

 

this unit DOES NOT WORK.
replaced ice pack 2 hours ago after finding temps at 82F.
just checked again, ice packs melted, temp 82F.
I think (know) the pump is too big.
I'm going to freeze larger amounts for now, or just switch out the plant

 

well, I'm just about done and had enough of this. Found this unit:

I think considering the problems I'm having, maybe this is best for a self enclosed system. It has a temperature controller, runs at 72W.
I'm going to rip the pump out and just use the cooler as a bubbler for now. But I do need to get this right.

 

the cheapest DWC I've seen is from Ronald Kleinman.

 

np prob sticky, always a pleasure to work with u

 

I'm actually sold on the top drip (or aeroponic) systems that I've designed. I can keep the reservoir separate (and small), place them into a small chest-style deep freeze set to 18C and have several plants running from different reservoirs. I really like these systems as they have produced the largest amounts ime. Something like this:

Its a lot easier to check the reservoirs and have the plant scrogged and left alone. That system was using 2min on/10 min off timer on and aeroponic misters.

IF I revisit this, I would create an independent reservoir that cools on demand (by integrating peltier elements throughout). Its just Peltier elements are not as efficient as conventional (condenser type) coolers.
thanks for check, my brother @Sirtootsalot. I will make a new journal soon, I am just waiting on some fem'd seeds.