Formalin/malachite green in reef tank glass/silicone

I have a 125g freshwater tank that has been treated for freshwater ich in the past. I have always used the same thing...Warley's Ich Away which contains malachite green. I'm getting ready to take down the tank and put it up for sale. I would like to inform the buyer if it is going to be an issue to set it up as a reef because of the treatments I've performed. The silicone is stained with the greenish blue hue. I know copper is bad and sticks to the tank and is "said" to cause issues, but does malachite green and formalin?

Also, whats a good price for this setup......I was thinking $300 firm?
125g freshwater tank, no scratches, slight blue hue on the silicone, black trim
Oak stand, painted black, 2 doors
glass tops-good condition
3-tube 48" t12 lights
Custom blue cold cathode moonlights
Rena xp3 canister filter 350gph
Magnum 350 canister 350gph
jebo canister 316gph
eheim 2236 canister 185gph (needs tubing to install)
125lbs black gravel
3 airstones with large dual output pump with 5 airline tube regulator

 

No one?

 

It won't hurt inverts if they want a reef tank. Just tell them to clean as good as possible.

As far as prices go, there's a LOT of variability in prices for used equipment in different cities. I would check out Craigslist in your area to see how the prices are.

 

Its going up for $300. Thanks for the help inwall. Just wasn't sure and i wanted to let the buyer know if there were going to be any issues with the ich treatments I've used in the past.