How does the silicone on this secondhand tank look? And is the bubble in the seam ok? My first big tank

[Shoebill]

Hi!
So I've followed fish keeping pages for a long time because I've always wanted a huge tank but lived in an apartment. I finally came across a used 75 gallon bowfront tank and am ecstatic - it's my dream tank! It used to be a fish store's tank and then the guy who bought it didn't get to use it.

I'm probably overly paranoid of aquarium silicone. It all looks really good except one seam and one bubble. The front left seam has a single bubble in it, trapped in the corner. The rest of the silicone looks fine on that corner. (pic attached). How much trouble would this potentially be?

The front right seam is where my question lies. It's a bit chewed up on the edges. Upon feeling it, it seems that it's just the thin edge that is chipping back to where the silicone gets thicker - it feels almost like when it was being smoothed the corner wasn't taped for an even silicone line and that's where it's real thin against the glass. You can see all the chips out of the edge all only go I towards the corner to a certain point, then stop where the silicone gets thicker pretty abruptly. I can't slide a finger nail under the silicone past that point, it feels pretty secure but I can't help worrying about it. I've never refinished a tank, but I've watched a lot of videos on how to do it and it seems... Doable, I guess.

Just based on pictures, what do you think? My basements already flooded once I don't really wanna deal with it again but my eye for solid seals isn't as good as I imagine yours are.

Pics attached, of the single bubble as well as the other seam. Please don't mind the clear silicone chunks inside, I'm removing the overflow boxes mounted to the back of the tank and slowly cutting the adhesive off.

 

[PheonixKingZ]

@Deanasue is good with silicone, consult with her. Good luck.

 

[FishGuest5123]

@Deanasue is good with silicone, consult with her. Good luck.

No, not me. Perhaps @AbbeysDad ?

 

[Shoebill]

I can add a few clearer pics after work also - I snapped these ones this morning, I didn't realize they aren't as clear as they could be!

 

[PheonixKingZ]

No, not me. Perhaps @AbbeysDad ?

Oh, sorry. It was @Byron, conslut with either him or @AbbeysDad.

 

[seangee]

At the end of the day you have the actual tank and we only have pics. Also there is no risk to our basements. Why not just test it (preferably somewhere where it won't do any damage).

 

[FallenPepper]

Reseal itll fail eventually and it's not too difficult or expensive to do it. Just make sure to let the silicone cure and slowly fill the tank by a few gallons a night and check the next day for leaks after. Learned the hard way lol

 

[PheonixKingZ]

I say just test it, don't put any substrate/décor in until you know it is safe.

 

[Colin_T]

most of the silicon looks ok but the pictures aren't the best.

if the silicon goes milky white then it's stuffed.
if the silicon is hard to the touch, then it's on it's way out.

good silicon will be firm but squishy and should be a uniform colour (black or clear).
if the silicon has been stained sometimes it will be a light blue in colour and that is fine as long as it isn't hard or brittle.