I picked up a 150 qt Igloo to replace my existing 2-plant DWC tank and looking for some experiential plumbing guidance. As with my current, DIY tank, I plan to put 2 x 1 3/8" holes in the side – one below the water line and one above – for bulkheads to run 3/4" PVC to/from my chiller. A few questions;
Any clue as to the material that lines Igloo marine coolers? I think it’s HIPS (high-impact polystyrene) but not positive. Maybe polyurethane?
The cooler walls seems thin and I’m wondering if it would be wise to laminate a 2" square piece of the same material to the inside wall to support the bulkhead. Good idea or overkill?
What kind of adhesive would you recommend using on the inside that maintains a watertight seal when it’s submerged?
Take a look at Hayward bulkheads. Those are good but pricey. Ebay is your friend there. I’ve used large step drill bits for such things. Avoid the punch dies since the insulation will compress and you’ll just distort the outer surface.
Adhesives, and their reliability, are very much dependent on the types of substrates being bonded and the prep. Plastics, particularly low surface energy plastics such as HDPE, require adhesives specialized for that particularly if submersed for a water tight seal.
I’ve used the following successfully for HDPE at the bottom of stations and reservoirs: Scotch-weld 8005 structural plastics adhesive. I’d look that up and then browse the list of their other products to find one most suitable for your needs. On my system, three years and the bond has held up perfectly. Also, pricey, unfortunately but it’s piece of mind.
The outer shell is probably HDPE but the interior is a different material, same/similar as the panels that line a refrigerator. This is my primary problem: Without knowing what the material is, selecting the wrong cutting method or adhesive can ruin the project.
Perhaps, the bulkheads with gaskets may be sufficient. Spread a thin layer of Molycote 111 on the gaskets. Don’t over tighten, try to keep the surface as planar as possible.
If that doesn’t work, it should be a recoverable situation until a suitable adhesive can be found. Usually the plastics will have markings somewhere and certain adhesives will work for a variety of materials. Most plastics I’ve seen for the higher end coolers are of the low surface energy type (makes cleaning easier and less staining).
I’m curious as to an insulated rdwc reservoir. The bulk of the fluid is, overall, being circulated I’d imagine. Are you also insulating the individual stations and such? Just wondering. I’ve used the insulated cooler technique but more for using it as a glycol reservoir.
Someone else may also have some other techniques. Hang-on to give them a chance to chime in as well.
The cooler/reservoir is the “station”. 2x hydro baskets sitting in 2x 6" holes in the lid under 400W of full spec LED with roots suspended in 100 liters of nutrient. Lower 1/2" outflow from the tank goes to a chiller outside the grow room, then returns by 3x waterfalls close to the top of the internal tank. Going to a cooler resolves 2 issues over my DIY tank: 1) (Hopefully,) No more leaks from seams, and 2) Right now my chiller kicks on about every 40 minutes for 5 minutes. With better insulation and an inline pump, I expect to greatly reduce the operation of the chiller. Eventually, I might consider moving the rez outside the grow room and use a couple of 30 liter coolers for stations, , perhaps doing away with my chiller, but no need to complicate things when it works well.
Hey Guys!! I’m actually gearing up for harvest this weekend and then am augmenting my DWC to be an RDWC just as you’re outlining! Up to now I have only drilled into the lids but the coolers I bought are polyurethane and ribbed internally. I had no issues with the lid and am expecting to use a watertight caulking seal no matter how tight I think I’ve got it sealed!
For your specific cooler though, find the actual manufacturer model number, Google that along with the name of the company and you should be able to find the spec sheet and breakdown of your exact cooler like I did for mine:
I purchased 12x 2 inch bulk heads from marinedepot.com and am very happy with the quality of them not a single leak in a big 55+ gallon system.
Only thing is marinedepot has been bought by a different company since then Bulkhead Fittings - Bulk Reef Supply. Not sure if they are selling the same product.
i have big regrets not taking advantage of the clearance sale they had when they sold lol. I should of bought the stuff for another RDWC
I really enjoy growing in the coolers, I live in the desert and have trouble keeping my water warm enough! In fact, I have small fish tank heaters not currently in use but installed and ready to turn on if my water gets too cold!
My goal is to fine tune a RDWC so despite the heavy fluctuations at times, to almost not need to touch it! I have an auto feeder/pH adjuster I will use for the first time next grow as well! Currently, I manually adjust and check the pH and if you work you simply can’t be there all the time.
As I build out my system and you yours we’ll have to let each other know what works and what doesn’t but you got a build buddy on this @Varinaut!!
I’m in the process of starting one on my very next grow. I’m going to be doing a side by side grow using a single RDWC with TWO tents. I will be testing the Medic Grow EZ8 against the Fluence SPYDR 2P by Osram. My goal is to keep as much the exact same as possible except for the lights and a few other things that won’t effect the outcome… ie the tents I have are different but sized exactly the same. I’ll also be using sibling seeds, not clones. Outside of that they’ll be a part of the same RDWC so they’ll have access to all the same nutes and be controlled by an auto feeder/pH adjuster.
I fully expect the EZ8 to work as well as the Fluence but we will see! It’s half the price and after using it to finish my current grow, can tell you it’s worth the savings even if it doesn’t 100% match the Fluence light… should be pretty damn close!!
And I am working on getting a website running! I own the web link but am not as savvy at getting it setup as I wish I was! I will hopefully have www.CoolerGuy420.com up and running soon though! I am also not shy to accept help from anyone who might be willing to help out in that endeavor!
Thanx for injecting some expertise into the thread, @CoolerGuy . I’d already googed for the cooler in hopes of finding a detailed spec sheet, but the closest I could get to the material used to line the cooler interior is: “plastic”. Thanx a bunch, Igloo.
What’s your experience with adhesives and coolers. Any reliable glue that sticks and holds a water tight seal? What do you use to make holes?
Finding spec sheets is literally part of my day job! Sometimes MFR’s don’t make the info easy to find, I had to go to a distributors website to find the one I screenshotted so if you want to let me know the model number I’ll see what I can find for you.
As for the actual RDWC build, I haven’t done one yet and only used my coolers separately so I don’t want to recommend anything for water tight sealant but I will let you know if what I try is successful! Two of my four coolers are still in use for hopefully no longer than this weekend!
As for the holes, any quality drill will do but I’d use a hole dozer from a set like the one below with a lot of teeth for a nice smooth and even cut. If you have a drill with a level use it! If not buy a small magnetic level, stick it to the top of the drill and eyeball it as you drill to keep everything as even as possible.
really appreciate your input 
