DIY 65 Gallon

LesbianChap

Don't ask, I'll tell.
Jan 2, 2006
188
8
18
Florida
Well, I recently read a long thread on cichlid-forums about how a guy made a large (800gal) tank using Drylock as the sealant. After pricing some stuff, I realized Drylock ($20/gal) and Hardiboard ($10 for a 3x5 sheet) would be a lot cheaper then plywood ($35 for a 4x8 sheet) and Epoxy (Sweetwater is $60/gal), and therefore I may be able to break even on tank smaller then 100gal...as I was already looking at buying a 65 gal from Glasscages, I knew the dimensions I wanted and the price for an all-glass.

Anyways, here's my diagrams from Google Sketchup. Sorry for the lack of colors, but I'm sure ya'll can figure it out, especially using the construction/cuts list below.

A little more explanation on the design: I'm using 1x6 for the base, and 2x4 for the rest (except the back top which is a 2x4 cut in half to make a 1x4, in case I ever decide to use a HOB, I hear few are designed to work on walls wider then 1.5"). The walls/base are 1/2 "Hardie" board...if you don't know what that is, it's water-resistant concrete panels they use to go behind tile...search "Hardie" at Home Depot, and make sure you're looking at both In-Store and Online merchandise and it should pull right up. The glass is 3/8", and covers the full front of the aquarium to be silicone'd in after the Drylock waterproofing. As far as I have been able to tell, one gallon of Drylock should be able to do at least 3 coats on all Hardie Board. The Quad is for the joins between the Hardie Board before the Drylock is put on...it's flexible like Silicone, but it's made for concrete and painting so the Drylock will stick to it. The glass will prolly be 1/4 shorter then the dimensions listed so it'll fit after the Drylock is applied...I hear people often forget to account for thickness it adds to the surface of a material.

Inside Dimensions are: 48x17 5/8x17 (the 65gal all-glass is listed as 48x18x17)
Outside Dimensions: 52x22x19

Now for my pricing for the construction:
Code:
$15.00	5 - 2x4 8' pieces ($3/board)
$ 8.00	2 - 1x6 8' pieces ($4/board)
$21.00	2 - 3x5 1/2" Hardie board ($10.50/ea)
$22.00	1 gal Drylock
$ 4.00	1 tube Silicone GE 1
$ 4.50	1 tube Quad
$40~	Glass - 3/8" thick, 48x17 (size rounded up) (Estimate from Glasscages.com, undelivered)
114.50	TOTAL

Incidentals:
Screws(~$10-15) (2.5", 1.5", 1.25", 1"), Glue (Liquid Nails, $1.60/tube), Bondo (~$10)

Same Size All-glass from Glasscages, $140 including shipping ($110 before shipping)

1x6 Cuts:
1: 52", 22", 19"	- 3" left
2: 52", 22"		- 22" left
2x4 Cuts:
1: 52", 19"x2		- 6" left
2: 52", 19"x2		- 6" left
3: 52", 18"x2		- 8" left
4: 52", 18"x2		- 8" left
5: 18"x5		 - 6" left
Hardieboard (60x36) Cuts:
1: 49"x19", 49"x17"	 - 11" left one way, no spare the other. (11x36)
2: 49"x17", 17"x18"x2	- 11" left one way, 1 or 2" between the other.

Lid/cover sizes:  Left to right: 21.75", 19" front to back.
So after incidentals (which I'd be buying to make a stand anyways), I'm breaking even, unless I missed something. Anyone have any comments? Notice something I missed?
 
I realize that plywood tanks get a lot cheaper then commercial ones around-about the 100g range. Some say 75g. I was merely doing a cost-analysis of a DIY vs Commercial when I started this...Before when I was looking at using epoxy, there was no way that I'd break even. Now, using Hardie board and Drylock, i can break even on a 65g...I figured I could make a 200gal for about $200, but I don't want such a large tank atm...merely the 65.

Seeing as I'd break even, I figured I might as well go for it...nothing like looking at something and saying "I did that."
 
I also realize the determining factor will be the glass cost. I'm ESTIMATING the glass cost based on an online source, and not including shipping. I'm hoping when I finally get home to build this I can find a local supplier that can match or beat this price...otherwise there's no way I'm "breaking even" on the build.
 
I'll be interested to see how that cementboard holds up, if you go through with the project. I built a 200gal plywood tank over the summer. The only thing I would be concerned about is its brittleness...I'm not sure how much water depth the stuff would handle, but it seems pretty sturdy. The glass I got locally was 1/4", a pice about 60"x18" and cost me a little over $50 so your estimate is probably pretty close.

What kind of construction method are you going to use - seal teh boards individualy then seal them together as you would a glass tank, or is there a method of joining them together to form the box and then sealing the inside?
 
I wonder if any DIY ers out there have tried to glue a pond liner to the inside of a plywood tank. This seems to me to be easier, and more durable than trying to coat the entire insode with epoxy or fiberglass resin... Just a thought...
 
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