Hello; Here is a revised old post about sealing a tank with silicone. Resealing a tank can be a chore and may not work the first time, but if you get a good seal it should last for years.
I have found that trying to run a line of silicone only on a portion of a tank has often not worked out very well. If a tank leaks, I find it best to reseal all the corners and sides at the same time.
-(In my experience the silicone needs to be applied in all corners and sides while it is still tacky so that it will bond to itself at the apex of each side.)
-(New silicone does not seem to bond to old silicone very well)(Some have posted that it will stick better to the old if the old is well cleaned, I have yet to test this myself.)
I also cut out the existing silicone with a utility knife from all corners before trying to seal with new stuff. I find a shop vacuum a handy way to remove the bits of silicone. If the first application of new silicone does not seal the leak, I cut out all the silicone that I have just applied and seal the whole thing again. I also find that the silicone tubes that fit in a caulking gun to be the handy way to apply silicone. The tubes of silicone that you squeeze with your fingers are just too hard for me to control and I have not tried to use them in years. You can plug the end of a big tube of silicone with a nail or something round to keep it from curing too quickly, as you may need it again.
-(Note – When you cut the end of a silicone tube, make the first cut near the end so as to have a small opening. You can always cutoff a little bit more if the bead of silicone is too small.)
Some additional pointers. I usually give a tank a good cleaning before applying the new silicone. I use a paste made from ordinary table salt (Without iodine) and a soft sponge.
-(I do not use a sponge or cloth that has been used with soap or chemicals.)
-(I have buckets and sponges that are used only for my tanks.)
The salt paste does not scratch glass and does a fair job at removing the deposits from the surface of the glass (be sure the sponge or cloth used to apply the paste with is not coarse enough to scratch the glass on its own and watch for bits of gravel that seem to jump into the salt paste.) (Letting the salt paste dry to a haze should desiccate most critters if you want to disinfect a diseased tank.)(Note- wetting the glass will soften up the deposits somewhat.) (Also for stubborn mineral deposits, a razor blade in a holder that gives a firm grip is useful. Use a shallow the angle on the blade and keep an eye on the corners of the blade. The corners sometimes get bent and will scratch a thin line. Rinse the salt paste out and let the tank dry well.
Once the tank is clean, I think it needs to be very dry before applying a bead of new silicone. Dampness tends to hide in the very small seams and in the corners of a tank. I suspect that dampness prevents the silicone from bonding properly to a surface and may result in a leak in a good looking seam. It can take a while for the moisture to dry out of the small seams.
... Anyways i was wondering while im soaking up watter should i reseal and then move it back or soak up thw water get ot settled then reseal... Cause i know moving stresses joints but its only one move and i have my fish in holding tanks and i dont like it lol
