4000 gallon plywood build

[floridafishlawsuck]

My 4k gallon plywood build 14ft long x 10ft wide x 4ft tall. Has been setup and running for over a year. This was an upgrade from my 1000 gallon liner pond.

Building process
I built the pond in my two car garage to better maintain temp during the winter. Old 1k gallon pond was outdoors in a screened in patio in North Florida. Was able to maintain tropical temp with one 800watt heater. The design is mostly off of AquariumDomain 4500 build. Total cost was around $5-6k for just the pond
Started by making a level base to account for the 1.5” grade of the garage. Needed to have a solid level base so weight of the water filled up wouldn’t case pressure points and cause a crack

I framed the bottom of the tank with 2x6

Laid down two layers of 3/4” hardwood plywood on the bottom for a 1.5” base

Started the walls by stacking 5 2x6x10 all the way around using many 3” screws and construction adhesive to attach. To save a bit of money and time I used the framing method for the middle of the walls then added 5 more stacked layers on top

Installed 3/4” hardwood plywood on all the walls. Filled in all screw holes with wood filler and sanded to prep for fiberglass

Every seam was fiberglassed with 4 layers. Bottom has 3 layers and walls have two layer of glass

I went with pond shield for the waterproofing. Ended up coating with 4 layers alternating colors each coat for best application. I was able to get a full coat with a 3gallon kit
Was able to score a 4x8 1.5” sheet of acrylic of market place for $600. Attached it to the pond with 6” lag bolts and a silicone seal. Used 8 tubes of silicone for a thick seal
Painted the outside with exterior paint

Filtration
The pond is filtered with two diy filters. Each filter is run with a 5000gph pump on different circuits in the event of something happening one filter will still be running.
Left side filter is a 100gallon stock tank with 6 cubic feet of k1 media fluidized. Has a poly fill mat as a prefilter for water polishing


Right side filter is a 55 gallon drum filled with 400 pot scrubbers, 20lb of ceramic media, and around 1000 bioballs with a poly fill mat prefilter.

Heating
I only need to heat the garage for around 5 months out of the year in my climate(North Florida). I heat the garage with a 1500 watt dr infrared space heater. The infrared heater works the best cause it heats the objects in the room vs the air. I have it set to 77 and it keeps all water in garage at 76-77. Once weather warms up the only need to run a small 100watt dehumidifier to keep humidity down. When it gets too hot in garage during the hottest part of the year a just crack the garage and run a box fan to circulate air

Pond maintenance
I only go into the pond once every other month to wipe down the panel and scrub a bit of algae off the walls. I change out the poly fill polishing mat on the filters once a week. For water changes I use a drip system at about 9gph rate. I’m on city water so I run it through a 3stage filter to remove the chlorine. I also have one of the filters piped to an exit if i need to get rid of water fast. With the drip I maintain under 20ppm nitrates


Watts used
For those who are interested in watt usage
Pumps 180watts X2 (24/7)
Air pump 40watts (24/7)
Lighting 3x shop light 45watts 12hours a day
Space heater depending on weather 5-25kwh a day
dehumidifier 3kwh a day when SH isn’t running

Daily 10kwh no heating of dehumidifier

 

[floridafishlawsuck]

Current fish stock
Firewood catfish(36-40”)
Redtailxtigershovel nose hybrid (30-36”)
Wallago catfish
Redtail catfish
Marble acara hybrid
Red belly pacu
Albino giant gourami
Florida gar
Silver arowana

 

[thebiggerthebetter]

Awesome work and report! A great example for all of us.
Is this your first build of the kind?
How long would you expect it to hold water trouble-free?
How old is the firewood catfish?

 

[floridafishlawsuck]

Awesome work and report! A great example for all of us.
Is this your first build of the kind?
How long would you expect it to hold water trouble-free?
How old is the firewood catfish?

Thank you. This was my first plywood type build. My last pond was a 4x4 post stacked box with a liner in it. I tried overbuilding it as well as I could to be long lasting. In the plywood tank build group on Facebook people say they had tanks last 10-20 years but I’ve seen others fail with the first year. With it being out of the elements and not doing large water changes it reduces the stresses. I got the firewood 2 years ago at around 16” and it has been a great eater when established. It hand feeds at the surface now. Photos are when I got it and yearly growth and how it sits waiting for food at the surface. Hoping to get mine shedd aquarium size

 

[danotaylor]

Wow

 

[jjohnwm]

My infrequent contact with some of the folks who adopted many of my old plywood tanks reveals that at least 4 of those tanks are still percolating nicely in their third decade, and many more are in their second. These are all smaller than yours, all are 24 inches tall, using 1/2-inch glass and regular 3/4-inch plywood construction. Sealed with various commercial epoxies, no fibreglass anywhere. All of them were exposed to years of constant large-volume water changes, which I think is a major wear factor as the tanks flex back and forth, in and out with each change.

I have only three plywood builds at home now, the oldest at just about 10 years. I expect it to last as long as I do (I'm 68).

Honestly, I think that the people who get long life out of their plywood builds are those who are careful and take their time to design well and then to do the actual construction in a painstaking manner. The threads that start out with a gungho design that leaks the first few times it is test-filled, requiring draining and repairs and modifications invariably sound like "Yeah, I slapped this on here, wanted to get to this point by suppertime, need to apply three coats of sealant tomorrow, blah, blah, blah..." A narrative like that always make me cringe. The old saying "measure twice, cut once" actually refers to much more than just cutting.

Read manufacturers instructions regarding materials like sealants...and then follow those instructions. Measure carefully, mark everything square, cut straight lines, pre-drill holes, use appropriate clamps and jigs and holding fixtures, buy quality hardware and tools, and don't set a time limit. Stuff always goes sideways at times; when it does, attend to it carefully rather than just powering forward.

This thread is a breath of fresh air. Awesome build, not high-tech, just plain old careful work, common sense and attention to detail. I love it!

 

[floridafishlawsuck]

My infrequent contact with some of the folks who adopted many of my old plywood tanks reveals that at least 4 of those tanks are still percolating nicely in their third decade, and many more are in their second. These are all smaller than yours, all are 24 inches tall, using 1/2-inch glass and regular 3/4-inch plywood construction. Sealed with various commercial epoxies, no fibreglass anywhere. All of them were exposed to years of constant large-volume water changes, which I think is a major wear factor as the tanks flex back and forth, in and out with each change.

I have only three plywood builds at home now, the oldest at just about 10 years. I expect it to last as long as I do (I'm 68).

Honestly, I think that the people who get long life out of their plywood builds are those who are careful and take their time to design well and then to do the actual construction in a painstaking manner. The threads that start out with a gungho design that leaks the first few times it is test-filled, requiring draining and repairs and modifications invariably sound like "Yeah, I slapped this on here, wanted to get to this point by suppertime, need to apply three coats of sealant tomorrow, blah, blah, blah..." A narrative like that always make me cringe. The old saying "measure twice, cut once" actually refers to much more than just cutting.

Read manufacturers instructions regarding materials like sealants...and then follow those instructions. Measure carefully, mark everything square, cut straight lines, pre-drill holes, use appropriate clamps and jigs and holding fixtures, buy quality hardware and tools, and don't set a time limit. Stuff always goes sideways at times; when it does, attend to it carefully rather than just powering forward.

This thread is a breath of fresh air. Awesome build, not high-tech, just plain old careful work, common sense and attention to detail. I love it!

Thank you. I made it to stay if I ever move it’s staying with the house lol. In total I used 75lb of screws, over 40 tubes of construction adhesive, 12 gallons of fiberglass resin, and double the layers of pond shield the manufacturer recommends. I learned pretty quick that my 1k gallon wasn’t gonna be enough for long so I started planing it out early. Over a year of just planing and drawling out designs and then a year of construction(mainly working on just the weekends) I’m happy with the outcome and most likely gonna build another 2k gallon across from it for the less aggressive monsters. Had a bit of experience building plywood reptile enclosures that helped me understand cutting and measuring carefully but nothing that needed to hold water. A lot of people in my area just use pool pond but I didn’t want to follow the pack. Now I’ve had a large tank with a viewing window I don’t think I could ever go back to just a top view pond.