obviously you have skills it's holding water and looks great. .... that room is awesome why the walls and ceiling not rocked up and painted with exterior paint , 1/2" tempered glass is strong enough as you said , seam strength will need good attention , even seam armored with additional glass pieces , I have no idea if know that giant air pumps made for septic systems are available in many sizes , drive a good fan across the water surface will cool things down , wow lol , goldies enjoy sifting through sand , large pool filter sand , if I may 1" stones doesn't allow this , big water changes often is key with monster aquariums right ,
Thanks for the Friendly Commentary, it will make a great Self Report! Let us begin, Shall We?
Parka
, Self REPORTING with Vigor and Gusto!
1. Ceiling and Walls. Especially the ceiling. Holy Smokes would I ever like to get all that insulation covered up with... Something! I hope it will happen before the New Year. I can't work on the ceiling on account my arms ain't long enough! Dang it!
2. Agree on the glass, thank you.
3. Seam Strength. I have it in Spades! Those very long butt joints are glued and screwed and I use a pocket hole jig to make very strong joints. That's Chicago before the second layer of plywood is fastened on.
4. Large air pumps. I would like to learn how to use air instead of those fun pumps. I like Pumps! See for yourself! In front of the pumpers is the Official Naval Fleet of the City Series of Aquariums. The Laws of the Waters Shall be enforced with Vigor & Gusto! There has bean Vandals about...
Water Changes. The tap water showed zero ppm nitrates and Chicago has been up for one month and the nitrates look like this:

Maybe 40 or 50 ppm? Also after one month I can visually tell that the pre filters are ready to be swapped out. And then after the new filter boxes are in place, the old filters can be cleaned at my leisure for the next swap out. I thought it was cool how you compared a UG filter to a septic system, I guess that's exactly what it is! I like to say it's the same process that municipal water treatment plants use. Anyway, a 50% water change, the tank size, no matter, 50%, Crap! 400+ gallons.
I have decided to not feed as much and I hope my plant plan helps to keep the nitrates manageable without too frequent water changes.
6. Water Temperature. It is holding at 72.3 degrees and the air temp is currently 77. Using a small fan to aid evaporation, I am so pleased with how well that works. I will be happy if I can keep the water below 80 degrees, 78 even better!
7. Gravel. I dry sifted the gravel in four grades from course sand, fine gravel, medium gravel, and the full size pea gravel. It made rinsing the pea gravel much better minus those three lesser sized gravels. I used the pea gravel in the tank and I have buckets of the smaller sizes, very nice! The Goldfish just sorta pick at the bottom but those Koi, the GARGLE the gravel! I love my Goldies! They are smart and they recognize their tank mates. On two different occasions, I had my fishes separated for several days and when I returned John Candy to Akron, his tank mates mobbed him with Goldfish Love! And when I witnessed it a second time when Bumbles finally landed in Chicago, all of his Koi Friends were all over him! It was real and unmistakable, the fish were so alert and vibrant and pumped, so COOL to witness.
