# Repairing tank with cracked bottom



## R.sok (Sep 24, 2012)

I think it is a disaster waiting to happen. But if it were me & I was set on doing this without the correct bottom panel or just to test it for the hell of it, I would use silicone & put that "patch" on top & then place something on the outer bottom on the tank. Maybe a cut piece of wood so the pressure doesn't push through the lower crack.

I am not responsible for what you decide to do in case of a disaster, this is just an idea...


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## Revonok (Oct 17, 2012)

Thank you for the reply. I know it's not ideal but I'm hoping it will work, I guess I'll find out. I had planned to put some sort of reinforcement on the bottom side as you suggested, probably along the length of the aquarium but inside the plastic trim, in hopes it would allow the weight to be distributed more evenly.


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## Darkblade48 (Jan 4, 2008)

If you can't replace the entire pane of glass, then don't bother patching it, it is just a waste of time and materials, in my opinion.

It is also extremely risky, as the aquarium would not be any safer to use...


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## Revonok (Oct 17, 2012)

Have you ever attempted it or know anyone who has? I'm by no means arguing your point, I'm hesitant to try myself honestly lol I've just seen a few people saying they've done this with success.


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## Wy Renegade (Nov 29, 2011)

I hate to say it, because I also view it as a disaster just waiting to happen, but I do know some people who did it with a 125 gallon. Two pieces of glass, one above and one below, and lots of aquarium silicon and it has been up and running with a full reef in it for five years now without issue. It is most definitely not something I would do however.


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## JoeGREEEN (Jun 28, 2011)

*It can be done*

Ive patched side cracks before with no problem

I think if you use a piece of at least 1/8" thick glass and patch it on the inside of the tank and then place a piece of foam (like the pink foam & NOT styrofoam) on the inner bottom you should be fine.

I would go to a local glass shop and have them custom size a glass pane the size of the inside of the bottom and just silicone that on the cracked bottom.

Just be sure to use aquarium safe silicone (Silicone 1 by GE ) and put a good bead along all the cracks.


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## Revonok (Oct 17, 2012)

Joe, have you ever used that method for bottom cracks? It's a very small crack (maybe 2 1/2 inches) and the tank held water with the crack there, I just wanted to try and do what I could to help it not get worse. I'll keep you all informed so you can either say wow it worked or have a good laugh and see pictures of my friends ruined carpet XD 

Thank god my tanks are all okay >_>


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## R.sok (Sep 24, 2012)

My friend has done it before with a 10gallon running for a year with no disasters. he used the pink foam from homedepot, I forgot what thickness but it was slightly thicker than flush, with water poured in it leveled itself out & acted as a support. 

Again do this at your own risk & keep in mind even though the crack is only 2 1/2 inches it will spread over time. Idk how much used 30 gallon tanks go for in your area but around here they can be had 15-50 used..sometimes even free which is far better than the risk


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## JoeGREEEN (Jun 28, 2011)

This method has been done on bottom glass but not by me. (only back and side)

If your friend is desperate for a quick fix then use the glass you got from the 10G & make sure its siliconed inside of the tank and a good bead along each crack and use that plush pink foam cut to the inner perimiter of the bottom frame and place it below the tank. 

and even with all this I would stress test it outside after it dries over newspaper for 72hrs , just to make sure.


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## Revonok (Oct 17, 2012)

Thank you all for the replies and great info, it's much appreciated. Luckily I have plenty of that insulation foam board stuff on hand in various thicknesses so I'll see which fits the best and go from there. I'll keep you all posted if anyone is interested to hear the results. :]

Also R.Sok, I've looked locally online and in classifieds but apparently aquariums aren't popular around here, cause' I've found NOTHING. Lots of great stuff on AquaBid but not in my state and local pickup only lol


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## JoeGREEEN (Jun 28, 2011)

K' goodluck and keep us posted


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## joefish72 (Mar 10, 2012)

Revonok said:


> Have you ever attempted it or know anyone who has? I'm by no means arguing your point, I'm hesitant to try myself honestly lol I've just seen a few people saying they've done this with success.


 I repair and rebuild tanks and the short answer is yes it can be done. Note: There are no advantages to fixing a 30 gallon since you can buy one new at petco for $30 when they do the buck a gallon sale.


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## boxhead1990 (Aug 29, 2011)

It would be the same as putting a patch over where a tank has been drilled just make sure there's no air pockets and it will be fine chances are the crack doesn't leak anyways


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## hydrophyte (Mar 1, 2009)

It is generally much wiser to just purchase a new tank. Thirty gallons of water can do a lot of expensive damage.


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## JoeGREEEN (Jun 28, 2011)

*Petco says no to 30G tank in the dpg sale.*



joefish72 said:


> I repair and rebuild tanks and the short answer is yes it can be done. Note: There are no advantages to fixing a 30 gallon since you can buy one new at petco for $30 when they do the buck a gallon sale.


I have never seen petco sell anything besides 10g, 20L, 20h. *29G*. 40B & 55G.
and they charge tax for the full retail so for about $30 @ a dpg sale you are limited to 20 gallons.

since the OP has most of the materials, and if its done right & tested .it should work out.


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## [email protected] (Jul 17, 2008)

Which of the "go ahead and patch it" people are willing to accept liability for their suggestions?


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## Revonok (Oct 17, 2012)

Hello everyone, and thanks again for all the advice and replies. A little bird told me to keep an eye out after Christmas for the 1$ per gallon sale, and sure enough December 28th I went in and bought myself a brand new 29 Gallon marked for $29 with a 25% off cupon, needless to say it was a great deal. 

However, I also went ahead and took a gamble with my 30 Gallon. I put very thick beads along the cracklines themselves, removed and replaced the silicone on all edges, heavily siliconed the sides of a 10 gallon tank to the top and bottom of the tank on and around the crack area, and then cut some insulation foam to the proper size and placed it along the entire underside of the tank. I was very nervous while filling the tank with substrate and the hardscape, but here I am a few weeks later and the tank has been up and running just fine, I've been keeping an eye on the cracks and marked them initially with pieces of tape and a marker (obviously externally) and also took pictures, and none of them have spread or gotten any bigger. I know I was takin a big risk but it seems to have worked great and my girlfriend loves the tank. I'll post pictures soon but I just wanted to let everyone know that as of right now, the repairs worked very well. 

I know it's not ideal, but if anyone finds themselves in a similar situation and cannot afford to replace the entire tank I think if done properly this is a viable option (While still extremely risky)

*Edited for spelling*


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## Ardhendu Bhattacharya (Jan 25, 2018)

hydrophyte said:


> It is generally much wiser to just purchase a new tank. Thirty gallons of water can do a lot of expensive damage.


can I put a wood piece instead of glass piece(as mention above) in bottom cracked area with silicon?
Can I use M-Seal instead of silicon?

waiting for your valuable comments.

I know that bottom glass change and etc etc process. So, just give the answer on my queries.


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## Darkblade48 (Jan 4, 2008)

Ardhendu Bhattacharya said:


> can I put a wood piece instead of glass piece(as mention above) in bottom cracked area with silicon?
> Can I use M-Seal instead of silicon?
> 
> waiting for your valuable comments.
> ...


I'm not sure wood would seal well with glass.

Also, this thread is nearly 5 years old, so you may receive a limited response here.


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## Capt Nemo (Jan 26, 2018)

Fixing tanks is always an adventure. I keep all mine outside for a while to make sure all the pressure has equalized. But you're right, 30 gallons are cheap. I've even gotten used 50's for free. I only try to fix bigger ones -sizing up a 135 gallon next.


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## Olskule (Jan 28, 2010)

From watching online sources for used tanks, it seems like all the great deals are always on the East or West coasts, which sucks for us in the middle. I've built and repaired smaller tanks (<55 gal.), and I'd say patching is usually "iffy" unless you are completely covering the cracked panel with glass at least as thick as the original. I totally replaced the bottom of a home-made 55 once. The hardest part was making sure all the old silicone was cleaned off. I got it repaired and it held water just fine, but when I was first setting it up, my wife was arguing with me about the placement of a large rock, and reached inside to take it out of my hand, which resulted in the rock hitting the front glass and cracking it. I still have the tank, but not the wife. We got a divorce. Not over that, but later. I miss that tank.

Olskule


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## jeffkrol (Jun 5, 2013)

go to 3 min.. 
https://youtu.be/pG7C9GQRuA4

This is just plain funny.............
https://youtu.be/I_3WZ5YWndA


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## Olskule (Jan 28, 2010)

jeffkrol said:


> go to 3 min..
> 
> 
> 
> ...


I've actually done the exact same thing as the second video, but with a 10 gallon tank. It worked, but we're talking about a lot less pressure than with a 75 gallon. Also, I'm not sure he gave it every advantage or else it may have actually worked. If he had used the right silicone and not left so many air pockets, and had waited at LEAST 24 hours, he may have had a successful repair. Personally, I think he really wanted it to fail so he'd have an excuse to take a hammer to it. But if he REALLY wanted some drama/action from taking the hammer to it, he should have hit one of the solid panels instead; THAT would have been entertaining!

Besides, a repaired 75 makes a good low-water-level paludarium, or at least a terrarium. No need to destroy it for such little action–what a waste. 

Olskule


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