90 Gallon Aquarium Build

Hey guys, I am looking for some advice in building my first plywood aquarium. The internal dimensions are planned to be about 20"wide, 24"high and 43" long, totaling about 90 gallons. However, I wold like some outside input for my plan, and some stocking suggestions when I do get to that point. My goal will be to build the tank at least this summer, then start aquascaping and hopefully have it done sometime close to Christmas, it should be a slow process to save up for. I am thinking about a $550 budget max, but less is better. So far I've estimated $50 in wood and lumber, $80 in the sealant (I'm thinking Pond Armor), and about 70 for the glass/ viewing pane. Then about 120 in filters, with three Aquaclear 70s, but the third installed later in the process. As for heating, I am planing a tropical, so a 300 watt sounds about right, my room is already about 71-72ish. Sand is my preferred substrate, so about $50 dollars in that, and I want to plant it, so I'll leave a $40 budget for some plants (But easy plants), which adds up to $460 if I did my math right, although I may not have, which leaves me with about $90 left in the budget plans. Any other important equipment I should be remembering? I plan to have it as low tech as possible, and to try to cut down on prices a lot by buying used. However this is for all new stuff. Anyone notice any immediate problems? Anything I should have included, or prices that seem very off? Thank you for any advice, and also feel free to start throwing ideas out there for stocking. I am open to all suggestions, but I am thinking a tropical peaceful community, with a few schools and a few large centerpiece fish.

 

You can get sand much cheaper than $50. What color are you wanting?

You will also need silicone for the glass.

 

Make sure to us a fibreglass web at the seems and then cover with pond amour or liquid rubber. Both work very well.

 

For the sand I was thinking of a Black/White split. And I wasn't thinking about the silicone, good call.
And thanks for the Fiberglass web advice.

 

Unlike metal or plastic abs frames, the wood will adjust to ambient environment. While minuscule this movement could create a pinhole leak leading to a disaster. While not seemingly a lot of water, the inner force to the walls is quite hard, now add movement to the water and thus the reason to reinforce the seams.

I have a 500G Redwood Cedar indoor holding pond with 19 select koi ranging from 8 to 23 inches. The frame of this is 2x4 with a 2x6 lagbolted to the cement floor of the basement. The is also 2 airplane flap tether cables wrapped around and secured into the brick wall which used to be the firewall for a wood burner. Then a 1/2 presswood treated wall and covered with rubber(edpm) liner. The seams are painted with 5 layers of liquid rubber over a fabric mesh. I used 1/4'' lexon for the viewing window as it's stronger and more scratch resistant than acrylic or plexiglass.