Fish Tank Construction

10K gal, 18x16x5.5ft, full acrylic, thin 3/8″ acrylic skin inside a wooden box; started Feb 2020, stalled Feb 2021 for two reasons, namely, ran out of time (must open to public at large with business hours soon or face a failure to launch) and out of money (acrylic viewing window 12×5.5ft by 2 inches thick is roughly $7K from China and $14K from USA):
https://www.monsterfishkeepers.com/forums/threads/10kgal-40kl-fish-tank-16x18x5-5-5×5-5×1-7m-wood-box-3-8-9mm-acrylic-liner.738179/

1800 gal full acrylic tank made by conjoining two acrylic tanks of different height, [1] 1100 gal 10x6x2.5ft, crooked, badly broken in several places, & [2] an intact 500 gal 8x4x2ft; the tanks, acrylic panes, and glue cost us $2200; tanks came with stands, one is wood, the other is metal:
– https://www.youtube.com/watch?v=4jqtm9NU_jw
– https://www.monsterfishkeepers.com/forums/threads/1800-gal-acrylic-fish-tank-for-2200.728723/

25K gal, wooden box, EDPM rubber liner, 50x14x4.5ft tank, 1ft inground, 3.5ft aboveground, full-acrylic 45ftx3.5ftx0.75inch window, wet/dry filter, 60ft aqueduct, ten 6600 GPH pumps, just the tank cost us $6000 in materials:
– overview https://www.youtube.com/watch?v=3-MeiFQd7PI
– https://www.monsterfishkeepers.com/forums/threads/25-000-gal-rubber-liner-acrylic-fish-tank-50x14x5-for-6000.728724/

Two 4500 gal fiberglass tanks,13x13ft, with 8ft x 4ft x 2.5inch acrylic windows, made by Dolphin Fiberglass Products, Homestead, Florida, USA, come in 4 parts: installation, stands, seam fiberglassing, 14K gal sump filter and water reserve, eight 5300 GPH pumps: pages 7 & 8 http://www.planetcatfish.com/forum/viewtopic.php?p=276046#p276046
Repairing a separated seam: https://youtu.be/pGWr1cXXVf0

Our first tropical pond in the basement, first 25x6x3ft, 2500 gal, then extended to 40x6x3ft, 4000 gal: http://www.planetcatfish.com/forum/viewtopic.php?f=25&t=29488

12K gal koi pond with a stream back in Rochester, NY that we built totally DIY, 6ft deep, EDPM rubber liner (photos on the Yard is Canvas page):

Filtration

Overview: biofilters, water turnover, water change, 12,000 gal/day Reverse Osmosis filter system, pumps, drains, etc.:

All our tanks (50K gal) receive a continuous water change 5K-10K gal/day; temporary cascading overflows (all smaller tanks overflow into the 25K); DIY bulkheads for liners:

500 gal mechanical prefilter

The first iteration blew up in my face: http://www.planetcatfish.com/forum/viewtopic.php?p=280492#p280492

Second iteration stands fine today: http://www.planetcatfish.com/forum/viewtopic.php?p=280724#p280724

Two 4 inch pipes for the bottom drains of the two 4500 gal tanks

Do not use RPE reinforced polyethylene liner for indoor applications, especially if it would have creases. It seems the creases result in small, slow leaks in my experience because I used this liner to line the sumps for ten 240 gal tanks, double layer, only to get a slow seepage (replaced with EDPM rubber). It’s probably adequate for outdoor inground applications:
– https://www.planetcatfish.com/forum/viewtopic.php?p=278725#p278725

Slow leak, water is seeping from the end absorbed into the white towel on the floor

Do not use garbage totes for a long term filter. Sump filter out of 100 gal garbage tote: 4.5ft / 135cm high, filled with 1500 nylon mesh pot scrubbers with three woven matts on the top. First set up as a part-time siphon / dump flow filter, cycling between filling / no flow and emptying / siphon periods. But later found to work better if the siphon was eliminated. Overall, works great but the construction of the tote is not suitable to hold 4.5 feet of water pressure long term. After 2-3 years it started leaking (not the connections but the body of the tote): https://www.planetcatfish.com/forum/viewtopic.php?f=4&t=30141