Replacing top rim?
 

The top black plastic rim of my tank is bugging me. The two front corners have split from the salt buildup. This is a secondhand tank so the cracks were there already to start with. I have salt water seeping over and dripping (very slowly but eventually leaving a salt trail) down the outside of the tank. I guess because the rim is not fully sealed anymore and the water seeps under the plastic and over the top glass rim.

Not the greatest pic, sorry
https://live.staticflickr.com/65535/...fceb9e3a_c.jpg

One side of the plastic rim comes right off if I lift it. My question is, is it possible to get a new plastic rim? Is this commonly done and easy?
Please don't tell me my tank is toast, in which case just lie to me :sad:

I’m no expert on this matter. However I remember my 150g had the black plastic trim and I had similar cracks on the corner seams. I almost think it’s the design to make the square corner with the plastic trim. I don’t think it provides structural support of the tank and is more of a aesthetic function. Perhaps if that’s the case, just peel it off and all is well. I guess my fear would be if there is some ugly adhesive behind it. I don’t think by any means this would mean your tank is done for.

Last year a company out in Richmond called Delta Aquatics closed down giving away all their unassembled tanks ( parts for 10,000 tanks ) of varying sizes from 2.5 gallon and up. I recall they had such plastic frames so if you are able to find the a comparable size and aquarium maker, yes they exist but to ship the unibody piece, it will be expensive. The other alternative is to make something similar out of plexiglass. Lots of second ends out there for cheap to make something that looks decent. You need a table saw, or router and methyl chloride of course. Plexiglass can be easily painted black if can't find black colour sheets. Try Industrial Plastics or craigslist as a start. 1/8" or less should be more than adequate as it is more for cosmetic than structural.

Hmm ok so seems that the plastic rim is just for aesthetics to hide the top rim, and the issue will be sourcing a replacement.
I wonder if I should try removing them and cleaning all the salt etc off

I had the same thing happen.
I took an olfa knife and cut the silicone under the black plastic rim, inside and out. then you only have to gently, pull the rim off of the top edge of the glass.
Gently cause you do not want to damage it more.
After cleaning the glass and the rim from all the silicone and salt, I re-siliconed.
I think the top edge is the most important to seal, to keep the salt creep in check.
Before siliconing I cleaned with alcohol.
As well, I used bar clamps to tighten where the rim was split on the corner.

I may be wrong if you watch this video. However, my tank has held together well.
https://www.youtube.com/watch?v=KfpKh8DdJCs

Then there is this:
https://www.aquariumframeswholesale.com/frames-faq

And this is good for re and re the frame
https://www.aquariumframeswholesale....eplacement.pdf

Thanks Hillegom! Will check those out