My Igloo Marine's are 12gal each.
22L x 14W x 14H (outside inches).
20 x 12 x 12 (inside inches).
All white with some kind of UVA/B blocking shit on the exterior, according to Igloo.
Here's something I've never read or heard discussed about regular 5gal buckets.
Sitting and smoking some of that sweet Jilly, it's really no wonder why folks have probs with them buckets.
They are made from an industrial grade plastic and are to be used for everything except food storage.
They are not approved for food and beverage, like coolers.
Therefore regular 5gal buckets take on a different kind of chemical reaction to our grow nutes and plants.
Coolers, being made to store food and beverage long term, may have little or no chemical reaction.
Therefore they most definitely, to some degree of advantage, provide a more stable environment for Temps and PH.
After all, it's temps and ph that plague DWC growers the most and in that order.
Two things which very much go hand-in-hand and lots of growers fail to realize as well as understand.
I guarantee you, more stable temps (61F - 68F) will get you more stable ph.
The ppm's are up to the plant and what they feel like consuming.
But they can't get what they need without, TEMPS and PH, being stable.
Plus coolers are able to block out our intense lights and their heat effectively and efficiently.
I mean damn, they were made to be put in direct sunlight, which is 10,000 lumens/sq ft on the brightest day !
I apologize for the diatribe ! lol