Starting a 280 gallon plywood build

[DRteugelsi]

So, in the next month or two I will be starting the build on my 72''x48"x18" and from my calculation will be about 280 gallons.
The stock will be:
1 Polypterus teugelsi
2 polypterus endlicheri
1 Polypterus Bichir Bichir
5 Geophagus Winemilleri
1 Gold severum
I plan to add more polys as i go but that's just what I have now and what will be in there as soon as it's ready.

So, I had some questions about sealing the wood, I've some people use pond armor work fine and others have a lot of problems. I'm also looking into Max ACR but I wanted to not do fiberglass due to my little experience with it and I'm also building my sump as well. If Max ACR is the best option I guess I will go with that.

Also what size piping would be recommended for the sump, I was thinking of going 1'' but not sure if that will be enough.

Updates soon to come as I will be starting on the base if not this week next weekend

 

[Niners4952]

I used pond armor and loved it. If you can't work fast then mix half what you need cause once it starts drying you better be done. When I had my 300I had 2 1.5" drains and 2 3/4" returns

 

[DRteugelsi]

I used pond armor and loved it. If you can't work fast then mix half what you need cause once it starts drying you better be done. When I had my 300I had 2 1.5" drains and 2 3/4" returns

How long did you have the tank up? Because this will be extremely long term