DIY Stand/Canopy

[tsdid]

I have a question about staining/sealing a canopy and stand once it is designed and build. do you apply any kind of laquer or sealant once the stain is on to prevent water damage, Also will any of these chemicals leach into the tank and effect the livestock?

 

[scsinet]

Once I apply stain, I apply standard oil based polyurethane to the entire stand - every square inch. That means all the internal structure, even the bottom. All horizontal surfaces get at least 3 coats. The rest, at least 2.
Anyone who lives very close to the ocean will tell you that it's a very harsh environment. Protecting the wood is very important, because if it rots, not only does it look bad, it can impact the structural integrity of the stand.
As for leeching, it's doubtful. The water would somehow have to drip off the wood back into the tank, sump, etc. Generally this does not happen. Sometimes tank inhabitants splash the inside of a canopy or something, but that's an occasional drip - which even IF it contained toxins - it would be in trace amounts.