Should have this up and running first or second week of nextyear..
I'll post the allowed 5 pics and try and cover as many of the details as I can.. I bought the 13/16" deep hole drill off Amazon, 6-7$, It was needed to get a clean, straight hole through the ice chest insulation... It also works for the center hole in the washer/spacer.. A 13/16 spade drill will work for buckets when drilling holes for 1/2" grommets. The old 1-3/4" hole drill I had on hand.. The plastic washers used on the outside of the igloos are cut from 5 gal buckets... I also had 1/4" and 1/8" abs sheet on hand from other projects. Plastic washers for the outside of an igloos, I cut from the sides of 5 gal buckets.. Almost all the parts I use, or adapt, are bought off the shelf from HD..
Please bear with me as I go through this again, The pvc standing water column connected to the reservoir is what makes this setup work.. The water in the grow igloo, and the reservoir, and the water column are all the same level.. The top of 3/4" pvc water column is 6-7" higher than the water level.. As the drip ring removes 5-6 gal an hour from the water column, it is replaced from the reservoir... With the dripring adding 5-6 gal an hour to the grow Igloo, gravity will return the water, at the same rate, to the reservoir near the Ice Probe..
No matter how slow you think the circulation is, It's more than enough... The o2 added by the hydroton means no air stones needed.. For myself this has always been about removing all sources of heat.. I have a 1/10 hp chiller sitting in the wings..
This project isn't allowed in my Projects from my shop thread... No pot references allowed there..
When drilling the plastic washers/spacers, I drill the pilot hole with 13/16" drill, but not the hole itself.. That holes serves as the start hole for the 1-3/4" hole drill.. I drill out the 13/16 hole while holding the 1-1/2" plastic in a $2.99 clamp from HF.....