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Is it safe (for the fish) to use hot glue to put together glass for an aquarium? Answered

Will it harm them in any way? That's all I really need to know. Thanks!


is hot glue ok for guppies? i used some for making decorations in my tank.

One major problem with hot glue is that it quickly looses adhesion if suberged in water.
It is also hygrophobic and will swell up over time.
The only "glues" I use in fish tanks are:
A) Silicone rated for either aquarium use or rated as safe in enviroments for human consumption (usually for builders supplies).
B) Two component resin based glued labeled to be safe for underwater use and to be inert once fully cured.

A is for what I call general use, B when it comes to structural repairs like pump and filter housings.

Never use hot glue for pets it is highly toxix

No..hot glue is not meant for water uses.I used it to stick my turtle dock to the aquarium wall.The dock came off before i had a chance to put my turtles in the aquarium....The glue just dissolved in the water.Buy silicone glue for these kind of jobs.

Yep you are right.. i too tried but failed. Hot glue dosent last long in water.

Long time fish keeper and avid DIY'er so thought I would share. Crazy glue is safe for aquarium use. It can be used to glue moss or other plants to rocks in the aquarium. It cures quickly in water and is fish safe. Will not hold an aquarium together though. Hot glue will not hold up under water. It is safe to use but will not last. 100% silicon without mold inhibitors is what most aquarium keepers use. To repair a leaking aquarium remove the original seal with a razor blade or other sharp object. Be careful. Remove all old caulk and clean with acetone, fingernail polish remover. Place painters tape about 1/4 inch away from each corner on all sides. Squirt silicone into seam making sure it goes from top to bottom. Wet finger and slide it along silicone to spread it and work into corners. Let dry and remove tape. Photo frame glass is not a good idea for any tank over a gallon. It just will not hold the water pressure. Betas need at least 5 gallons. They may survive in tiny containers, a myth, but quality of life is not good.

personally, I don't allow fish to use hot glue nor to help build an aquarium (sorry, I just had too....I couldn't stop myself). :-D

You can get the 100% silicone caulk at any home center, they also come in smaller tubes so you don't need to get a caulk gun. Get the CLEAR stuff which goes on cloudy but dries transparent. Wear disposable gloves since that stuff does not come off your skin easily. Use a wet finger or popsicle stick to smooth out the joints. Practice first. Any leftover stuff you can caulk the windows on your house or around the bathtub... :)

Yes, but the big tube an the caulk gun are often cheaper than the small tube. ;-) Make sure it DOES NOT say "mildew resistant".

I don't know. They use it in hospitals on cuts, etc. . .

My mom tried that too i am not sure if it worked but it didn't seem to hurt the fish but it would probably dissolve

Actually I think it's inert when cured, but it's brittle and will crack because the glass will flex under the water pressure. If you are thinking of using the picture frame glass you mentioned in your other thread, you'll have to keep your tank fairly small. It would be better suited to a formicarium, or someother sort of dry vivarium, If you can cut glass and have any sort of woodworking skill, do a google for "Wardian case", they're retro-cool.

even the best of duct tape will have troubles once wet. We have some holding together an old Guinea Pig cage made of Plexiglas, and it peals away.....no water touches it at all.

Yes, the biggest problem with "super glue" or "crazy glue" is that it is not made to "fill gaps". So, it may hold well (if used exactly right, and if there is enough surface touching), but it will probably leak just as well as it holds.

The biggest pieces of glass are only about 7x5 inches... Ok, I'll look that up.

Picture frame glass, you'll be okay but make it five high by seven wide. no duct tape, ummm, if you want a fish tank you really need the silicone sealant, there's no getting around that, unless you want to go the very old route of making an metal frame and sealing it with bitumen (tar) ;-). I'd think of another option, small size like that you could raise caterpillars, doodlebugs (ant lions) or jumping spiders. (wanna guess what my room looked like as a kid ;-))

At that size, we're talking about 0.1 cubic foot (about 3/4 gallon). Enough to possibly hold one or two beta fish. Nothing more. And that's if you use no gravel!

Ok, I was wondering how much water it would hold.... I was just too lazy to figure it out myself....

And I forgot to add, if you're raising caterpillars, antlions or spiders, you can use hotglue of superglue.

Okay, and then you have to go to bed. Once upon a time, there lived a terrible pirate, know as the "Dread Pirate Tool Using Animal" and he had a HS biology project to test the water quality in the Souhegan River, and his clever idea was to build two identical aquariums, out of glass and bathroom caulk, fill one with river water, and one with DI/RO water and put fish into them and see if the fish experienced greater mortality in one tank over the other. Well imagine the Dread Pirates surprise when the mortality in each tank reached 100% in two days. It was not until many years later that the Dread Pirate learned why bathroom caulk is inimical to piscine life. The end, now go to bed.

Waiiiiiiiiiiit.....So will the caulk I have next to me work? It is kitchen and bath, Almond colored, 100% silicone, but mildew resistant. Or would painter's acrylic latex caulk work? I don't think it would be very good for my fish....


Nope, sorry, mildew resistant most likely means it contains chemicals that leach out and kill mildew (and fish) Like Caitlin'sdad said 100% pure silicone is what you need.

Coincidentally, I went to bed right after you posted that -- although I wasn't at the computer, so I didn't get to read it until now...

There are no coincidences, obviously, it was telepathy, unless it was just a coincidence.

+1 Aquarium rated glue is the best option.

well honestly i dont no but unless its a rly big tank, or it is special to u in some way, just buy another one. look in a thrift store, just bowls are up to 5 bucks, and there always there.

I don't know personally how it worked but my brother had a broken treasure chest ornament in his his aquarium and my mom used hot glue to fix it and the fish seemed fine. I might cause leakage though.

sorry for the double post but the i in the second sentence was suppose to be it

I, personally, don't think any fish should ever be allowed to use hot glue

Here is a tip. Your silicon should smell like strong vinegar. If it doesn't, don't use it. When you lay the bead, dip your finger in rubbing alcohol, and then run it along the bead to smooth it out, and seal it completely. Thats how handmade tanks are made.

I have seen hot glue fail when it gets wet and is not strong enough on smooth surfaces. You can peel it off of glass and when used to repair a shoe...it will eventually pull off. You would be better off getting 100% silicone adhesive caulk to glue the aquarium together. That has to "cure" for several days to de-gas it for fish(you will notice the vinegary smell). Good luck.