Seel on 220 doesn't look great

[jtl]

As other have said the inside seal does not provide any structural integrity. I suppose it could prevent leakage if the seal between the glass panes was compromised but that is not the purpose and it would be a temporary repair at best. I would carefully remove the inner seal with a razor blade, clean with acetone and very fine steel wool and reseal. I have built several tanks and resealed others so while not a pro I have had some experience.

 

[USMA36]

Since it's not leaking, I think I'll try and reseal it. Is there a difference in the silicone on the bottom and on the sides. The sides are clear and the bottom is black.

 

[jtl]

Since it's not leaking, I think I'll try and reseal it. Is there a difference in the silicone on the bottom and on the sides. The sides are clear and the bottom is black.

The only difference is color. Since the sides are clear and you are only doing the inside seams I would stick with clear. Just purchase a good quality silicone, my preference was RTV but that was because of it's superior adhesive characteristics.