Purchasing A Used Tank

[newb]

hey Rabbut,

it is an All-Glass tank. I believe the dimensions are 48 x 18-1/2 x 21. It is pretty thick glass. I am guessing very close to 3/8" thick.

The silicone is only starting to lift in one small spot and only where the silicone got smeared very thinly. I am guessing this may be lifting from the old owner cleaning the tank, just becuase the silicone is so thin. But with no experience or real knowledge, i don't know if this is normal or just the beginning of much worse problem. My fear is it is the beginning of a much worse problem and the silicone will keep lifting all the way back to the opposing piece of glass.

I like the package he is selling, especially the oak stand and canopy, but I can't afford a new tank or repair on top of the price already.

Thanks

 

[rabbut]

Well, any chance of a photo? If so, it will be easier to judge if it's cleaning damage or wear-and-tear. The first costs a £5 tube of silicone, some masking tape, some meths and a new razer blade. (about £10 for it all if you don't have it already) The latter is a bit more than that...

Also, you could try using the fact it needs repairs soon to barter the price down

Any braces on this tank, or is it one of ADA's Braceless jobbies?

All the best
Rabbut

 

[kcharley]

great advice and, warnings

i built a wooden frame to hold the aquarium. both to keep everything straight, and to ensure i could do the job, myself. i known people in the past, who have had failures because the tank was siliconed, slightly out of true.
it is not a job for the feint of heart, if you have the slightest doubt, DON'T EVEN TRY!

Hi Boboboy,

I'm a worrywart and a bit of a perfectionist. I still say go for it. Just prep the surface carefully. 90 gallons is a large tank if it fails. Try to place it where if it does leak it does minimal damage.

Cool that you built your frame. How did you level it? On mine I used the truest 2x4's for the top supports and still used a sander to take down high spots (shown by straight edge). I then put a 1" foam pad on top of it and then searched the "bone yard" of a stone dealer till I found an inexpensive piece of polished granite ($20) for the top. That polished granite is so level that I can't believe I have any stress on the seams from an uneven surface. If you have a different way, I would like to know.

OP, I just reread your original post. Can you tell if the aquarium has been sealed before? I did a lousy prep job on a 10 gal years ago, not removing the old silicone. It didn't seal the leak. I pulled it out a few months ago and while I was hosing it out the reseal just starting pulling out from the water pressure. Once started pulling it out by hand was pretty easy. Resealing that one is on my to do list but it is a ways down. Can you tell why the old silicone is pulling away? Did they have a reptile in the tank that clawed it maybe? 90 gallons is a big tank and I'm a worry wart (interpretation, I may be overcautious). If it is holding water now and hasn't been resealed previously and you can place it where if it does leak it won't do much damage and you can get it cheap and you have back up to temporarily house the fish if it does leak later on, I would be tempted to get it without resealing it. It is a judgement call, do what you are comfortable with and have a backup plan to save the fish. Good luck.

 

[kcharley]

Well, any chance of a photo? If so, it will be easier to judge if it's cleaning damage or wear-and-tear. The first costs a £5 tube of silicone, some masking tape, some meths and a new razer blade. (about £10 for it all if you don't have it already) The latter is a bit more than that...

Also, you could try using the fact it needs repairs soon to barter the price down

Any braces on this tank, or is it one of ADA's Braceless jobbies?

All the best
Rabbut

Hi Rabbut,

What are meths? I'm unfamilar with the term.

A razor blade for 10 pounds? Are we using different terms for the same tool. I find the razor blade based scapers difficult to work with. They are about $5 here in the states. I picked up a sharp bladed metal scraper from the paint section of a hardware store and use a file to keep sharp. It is much easier for me to work with. It cost about $15.

Silicone for 5 pounds? Here in the states the aquarium grade silicone I've found is $22 before tax and it has a strong acid odor. If there is something cheaper to use without the odor I would like to know.

May I impose further? Locally there is a guy trying to rebuild a 180 gallon and a 300 gallon. If you have the time, please comment on the instructions I gave him. I would hate to see either one of those leak. Following is what I gave him.

Hope the following helps. Sorry that it is kind of long.

I resealed a 22 gallon aquarium a few months ago. It is still holding water. I followed the advice of several experience aquarists who claimed that they have resealed aquariums and not had a leak for years.

Silicone will not adhere to silicone. You have to remove all silicone, but you don’t have to disassemble the aquarium. (There will still be some old silicone between the panes holding them together.) I started with a very sharp fixed blade paint scraper about 4 “ wide. It is not a “razor blade” type scraper. You could use one of those but I find the larger fixed blade a lot easier to use. I bought it at Home Depot. I use a metal file to keep it sharp. Believe me, it is much easier to use a sharp tool than a dull one. Be careful not to tap the glass with the scraper. Glass cracks or shatter pretty easily when tapped with a sharp point. You can also gouge the glass if you have the scraper at too steep an angle. Generally try to keep the scraper as close to parallel with the glass as possible. My first act to remove the old silicone is to score it with three times with one point of the scraper. I would work on one seam at a time using the point to loosen one edge of where the old silicone meets the glass. I would then do the other side of the seam and finally I would do one score down the middle. I wasn’t trying to get all the way through the old silicone, just enough to get started. I would then lay the scraper blade on the glass keeping it as close to parallel to the glass as possible and keep working the scraper under the old silicone. Work at it gradually and don’t push too hard so you don’t break the glass. Eventually you will be able to grab a section of old silicone with your fingers and pull it out. If you are lucky, you will be able to pull it out in large strips. You won’t get it all this way. You will have to keep using the scraper to remove the remnants. I kept doing this until the glass felt smooth to my fingers. When the remaining silicone gets real thin you can probably rub off the remainder with your fingers. Don’t worry about the silicone in between the panes. Just leave it in place. In my opinion, you will have to do this to all eight joints. I know it is a lot of work and I know some people do only one joint but silicone doesn’t adhere to old silicone. I wasn’t going to risk a leak by just doing one joint. Plus, the actual leak may not be where it appears on the outside. The leak may start in one joint internally and then work its way behind another joint before it shows on the exterior.

Once you have all of the interior caulk, clean all the joints with a non-petroleum based product. Also clean the exterior joints both corners and frames. Remember to do the bottom also. I used household isopropyl alcohol on a rag. Let everything dry thoroughly. I waited three days keeping the old tank in a finished basement room.

To reseal the tank you need aquarium grade 100% silicone caulk. I could only find it a pet store. The hardware store silicone is believed by some to leech chemicals harmful to fish. While it doesn’t make sense to me, I wasn’t going to take the risk. Unfortunately aquarium silicone is expensive, $20 or so per tube. I bought a tube that would fit in a standard caulk gun. (I’ve never had good luck with the squeeze tubes that don’t require a caulk gun. I just can’t get a decent bead to smooth out and by volume it is even more expensive than the tube caulk.)

With the caulk gun I would apply a bead to one joint, then dip my finger in household alcohol and smooth the bead pressing it in to get firm contact with the class and fill in any air pockets. I had several sheets of paper towels ready to wipe my finger clean. Also have a trash can or bag ready for the used paper towel I would then move on to the next joint. You do have to move quickly as the caulk begins setting quickly. You also have to do this in a well ventilated area as the caulk is quite smelly. I would wear a respirator if you have one. It is an acidic gas that will burn if you breath too much of it.

Once you have the interior joints done, I recommend you seal the exterior joints as well even though you only removed interior silicone. Turn the aquarium upside down and place it on a couple of old boards so that the interior isn’t sealed against the floor. You will need very little for the exterior. Just enough to cover the joints. Smooth it as again as with the interior joints. Remember to do the bottom as well.

Keep the tank dry and at room temperature for at least a week. Silicone needs time to cure. After a week, test fill it where if it does leak clean up is easy. I did this in my garage. Make sure the tank is on a level surface. A warped or uneven surface will stress the tank causing it to leak and possibly break the glass. Leave the tank sitting with water for at least a week. Sometimes leaks take a while to show up.

If it makes it through all this without leaking completely empty the tank and move it to where you want it. Support it from the bottom while carrying it. You don’t want to stress a joint by holding it on the sides. Again, be sure the surface you finally place it on is very close to level and is even (not warped,) Again this is to avoid stressing the joints. Good luck.

Sorry this was so long. The guy was willing to pay somebody to do the job. I am sharing what knowledge I've got free. If I had the time I would go help him for free for the experience.

Thanks Rabbut

 

[raptorrex]

Well, any chance of a photo? If so, it will be easier to judge if it's cleaning damage or wear-and-tear. The first costs a £5 tube of silicone, some masking tape, some meths and a new razer blade. (about £10 for it all if you don't have it already) The latter is a bit more than that...

Also, you could try using the fact it needs repairs soon to barter the price down

Any braces on this tank, or is it one of ADA's Braceless jobbies?

All the best
Rabbut

Hi Rabbut,

What are meths? I'm unfamilar with the term.

A razor blade for 10 pounds? Are we using different terms for the same tool. I find the razor blade based scapers difficult to work with. They are about $5 here in the states. I picked up a sharp bladed metal scraper from the paint section of a hardware store and use a file to keep sharp. It is much easier for me to work with. It cost about $15.

Silicone for 5 pounds? Here in the states the aquarium grade silicone I've found is $22 before tax and it has a strong acid odor. If there is something cheaper to use without the odor I would like to know.

May I impose further? Locally there is a guy trying to rebuild a 180 gallon and a 300 gallon. If you have the time, please comment on the instructions I gave him. I would hate to see either one of those leak. Following is what I gave him.

Hope the following helps. Sorry that it is kind of long.

I resealed a 22 gallon aquarium a few months ago. It is still holding water. I followed the advice of several experience aquarists who claimed that they have resealed aquariums and not had a leak for years.

Silicone will not adhere to silicone. You have to remove all silicone, but you don't have to disassemble the aquarium. (There will still be some old silicone between the panes holding them together.) I started with a very sharp fixed blade paint scraper about 4 " wide. It is not a "razor blade" type scraper. You could use one of those but I find the larger fixed blade a lot easier to use. I bought it at Home Depot. I use a metal file to keep it sharp. Believe me, it is much easier to use a sharp tool than a dull one. Be careful not to tap the glass with the scraper. Glass cracks or shatter pretty easily when tapped with a sharp point. You can also gouge the glass if you have the scraper at too steep an angle. Generally try to keep the scraper as close to parallel with the glass as possible. My first act to remove the old silicone is to score it with three times with one point of the scraper. I would work on one seam at a time using the point to loosen one edge of where the old silicone meets the glass. I would then do the other side of the seam and finally I would do one score down the middle. I wasn't trying to get all the way through the old silicone, just enough to get started. I would then lay the scraper blade on the glass keeping it as close to parallel to the glass as possible and keep working the scraper under the old silicone. Work at it gradually and don't push too hard so you don't break the glass. Eventually you will be able to grab a section of old silicone with your fingers and pull it out. If you are lucky, you will be able to pull it out in large strips. You won't get it all this way. You will have to keep using the scraper to remove the remnants. I kept doing this until the glass felt smooth to my fingers. When the remaining silicone gets real thin you can probably rub off the remainder with your fingers. Don't worry about the silicone in between the panes. Just leave it in place. In my opinion, you will have to do this to all eight joints. I know it is a lot of work and I know some people do only one joint but silicone doesn't adhere to old silicone. I wasn't going to risk a leak by just doing one joint. Plus, the actual leak may not be where it appears on the outside. The leak may start in one joint internally and then work its way behind another joint before it shows on the exterior.

Once you have all of the interior caulk, clean all the joints with a non-petroleum based product. Also clean the exterior joints both corners and frames. Remember to do the bottom also. I used household isopropyl alcohol on a rag. Let everything dry thoroughly. I waited three days keeping the old tank in a finished basement room.

To reseal the tank you need aquarium grade 100% silicone caulk. I could only find it a pet store. The hardware store silicone is believed by some to leech chemicals harmful to fish. While it doesn't make sense to me, I wasn't going to take the risk. Unfortunately aquarium silicone is expensive, $20 or so per tube. I bought a tube that would fit in a standard caulk gun. (I've never had good luck with the squeeze tubes that don't require a caulk gun. I just can't get a decent bead to smooth out and by volume it is even more expensive than the tube caulk.)

With the caulk gun I would apply a bead to one joint, then dip my finger in household alcohol and smooth the bead pressing it in to get firm contact with the class and fill in any air pockets. I had several sheets of paper towels ready to wipe my finger clean. Also have a trash can or bag ready for the used paper towel I would then move on to the next joint. You do have to move quickly as the caulk begins setting quickly. You also have to do this in a well ventilated area as the caulk is quite smelly. I would wear a respirator if you have one. It is an acidic gas that will burn if you breath too much of it.

Once you have the interior joints done, I recommend you seal the exterior joints as well even though you only removed interior silicone. Turn the aquarium upside down and place it on a couple of old boards so that the interior isn't sealed against the floor. You will need very little for the exterior. Just enough to cover the joints. Smooth it as again as with the interior joints. Remember to do the bottom as well.

Keep the tank dry and at room temperature for at least a week. Silicone needs time to cure. After a week, test fill it where if it does leak clean up is easy. I did this in my garage. Make sure the tank is on a level surface. A warped or uneven surface will stress the tank causing it to leak and possibly break the glass. Leave the tank sitting with water for at least a week. Sometimes leaks take a while to show up.

If it makes it through all this without leaking completely empty the tank and move it to where you want it. Support it from the bottom while carrying it. You don't want to stress a joint by holding it on the sides. Again, be sure the surface you finally place it on is very close to level and is even (not warped,) Again this is to avoid stressing the joints. Good luck.

Sorry this was so long. The guy was willing to pay somebody to do the job. I am sharing what knowledge I've got free. If I had the time I would go help him for free for the experience.

Thanks Rabbut

looks like good advice to me. everybody has their own little ways. but i would prefer to "reseat" the whole panel. not everyone does though, and they still seem, on the whole, to stay water tight. I use White Vinegar, as opposed to "meths" (methylated spirit).Any silicone will do, all you need is it to say "aquarium safe". 310mm costs £3.99 over here. stuff from the LFS, can be 10 times that price. try the diy section at Wal-Mart.

 

[kcharley]

looks like good advice to me. everybody has their own little ways. but i would prefer to "reseat" the whole panel. not everyone does though, and they still seem, on the whole, to stay water tight. I use White Vinegar, as opposed to "meths" (methylated spirit).Any silicone will do, all you need is it to say "aquarium safe". 310mm costs £3.99 over here. stuff from the LFS, can be 10 times that price. try the diy section at Wal-Mart.

Thanks Boboboy,

Good idea on the white vinegar rather than household alcohol. The water content in household alcohol bothers me (told you I'm a worrywart.)

meths = methylated spirits

I'll check Wal-Mart for the caulk. The caulk from Home Depot and Lowe's here specifically said "Not Aquarium Safe".

Thanks again.

I may go get that 84 gal yet. $100 for two aquariums, an 84 gal Oceanic (needs resealed) with stand and hood and a watertigtht 42 gal hex All Glass with stand. Just what I need, one more project.

 

[rabbut]

OP, I just reread your original post. Can you tell if the aquarium has been sealed before? I did a lousy prep job on a 10 gal years ago, not removing the old silicone. It didn't seal the leak. I pulled it out a few months ago and while I was hosing it out the reseal just starting pulling out from the water pressure. Once started pulling it out by hand was pretty easy. Resealing that one is on my to do list but it is a ways down. Can you tell why the old silicone is pulling away? Did they have a reptile in the tank that clawed it maybe? 90 gallons is a big tank and I'm a worry wart (interpretation, I may be overcautious). If it is holding water now and hasn't been resealed previously and you can place it where if it does leak it won't do much damage and you can get it cheap and you have back up to temporarily house the fish if it does leak later on, I would be tempted to get it without resealing it. It is a judgement call, do what you are comfortable with and have a backup plan to save the fish. Good luck.

Silicone lifting from the glass is either old silicone failing, damage from a sharp object (reptiles generaly don't do that much damage to seals) or just poor prep work Old silicone and silicone comming off due to poor prep werk must be re-done, as it will usualy fail within 6 months of starting to lift... Damaged silicone can be repaired with a "splice"...

What are meths? I'm unfamilar with the term.

A razor blade for 10 pounds? Are we using different terms for the same tool. I find the razor blade based scapers difficult to work with. They are about $5 here in the states. I picked up a sharp bladed metal scraper from the paint section of a hardware store and use a file to keep sharp. It is much easier for me to work with. It cost about $15.

Silicone for 5 pounds? Here in the states the aquarium grade silicone I've found is $22 before tax and it has a strong acid odor. If there is something cheaper to use without the odor I would like to know.

Meths are Methelated Spirits, though any alcohol based chemical will work At work, it's Johnson's flea spray... Razor blades are the cheapest tool to work with, and are disposable for when they are blunt after use. I find a disposable craft knife the easiest, but you need safety glasses with those. You are forsing them to flex, and this can lead to them snapping Any sharp tool should be able to remove the silicone without too much trouble

Silicone will not adhere to silicone. You have to remove all silicone, but you don’t have to disassemble the aquarium. (There will still be some old silicone between the panes holding them together.) I started with a very sharp fixed blade paint scraper about 4 “ wide. It is not a “razor blade” type scraper. You could use one of those but I find the larger fixed blade a lot easier to use. I bought it at Home Depot. I use a metal file to keep it sharp. Believe me, it is much easier to use a sharp tool than a dull one. Be careful not to tap the glass with the scraper. Glass cracks or shatter pretty easily when tapped with a sharp point. You can also gouge the glass if you have the scraper at too steep an angle. Generally try to keep the scraper as close to parallel with the glass as possible. My first act to remove the old silicone is to score it with three times with one point of the scraper. I would work on one seam at a time using the point to loosen one edge of where the old silicone meets the glass. I would then do the other side of the seam and finally I would do one score down the middle. I wasn’t trying to get all the way through the old silicone, just enough to get started. I would then lay the scraper blade on the glass keeping it as close to parallel to the glass as possible and keep working the scraper under the old silicone. Work at it gradually and don’t push too hard so you don’t break the glass. Eventually you will be able to grab a section of old silicone with your fingers and pull it out. If you are lucky, you will be able to pull it out in large strips. You won’t get it all this way. You will have to keep using the scraper to remove the remnants. I kept doing this until the glass felt smooth to my fingers. When the remaining silicone gets real thin you can probably rub off the remainder with your fingers. Don’t worry about the silicone in between the panes. Just leave it in place. In my opinion, you will have to do this to all eight joints. I know it is a lot of work and I know some people do only one joint but silicone doesn’t adhere to old silicone. I wasn’t going to risk a leak by just doing one joint. Plus, the actual leak may not be where it appears on the outside. The leak may start in one joint internally and then work its way behind another joint before it shows on the exterior.

In some cases, when the structural (bits between the glass) silicone has gone, or where the silicone is pealing off due to poor prep work, it is actually advisable to re-seal the lot Test the structural silicone after you have cut out the seams, by pressing outwards on the panes. If they move, you need to strip and start from seporate panes of glass If it does not move, you are correct is saying that the tank should not need stripping completely

Glass should not gouge through silicone removal. If it does, you are using the wrong tool for the job, or the tool you are using has a bust blade You would have to have super human strength to get the glass to break by pressing on the seams, so that's not much to worry about. The pane would pus outwards before the glass brake in that case anyway... It's sudden shocks that do in a pane, not gradually applied pressure

Otherwise, that section is OK

Once you have all of the interior caulk, clean all the joints with a non-petroleum based product. Also clean the exterior joints both corners and frames. Remember to do the bottom also. I used household isopropyl alcohol on a rag. Let everything dry thoroughly. I waited three days keeping the old tank in a finished basement room.

You need an alcohol based cleaner, not just an none-petrolonium based one... Bleach won't do much for grease, and that's a non-petrolonium based cleaner... I'd wipe down a few minuites before actually running the beads I'd apply masking tape after an initial wipe down with your cleaner if you are going for a neat finish, and then I'd wipe down again, leave it for 5min and then start caulking...

To reseal the tank you need aquarium grade 100% silicone caulk. I could only find it a pet store. The hardware store silicone is believed by some to leech chemicals harmful to fish. While it doesn’t make sense to me, I wasn’t going to take the risk. Unfortunately aquarium silicone is expensive, $20 or so per tube. I bought a tube that would fit in a standard caulk gun. (I’ve never had good luck with the squeeze tubes that don’t require a caulk gun. I just can’t get a decent bead to smooth out and by volume it is even more expensive than the tube caulk.)

Hardware trade silicone contains anti-fungral chemicals to prevent mould, and also has a different solvant base. The latter has questionable risk, but fungisides WILL kill fish

With the caulk gun I would apply a bead to one joint, then dip my finger in household alcohol and smooth the bead pressing it in to get firm contact with the class and fill in any air pockets. I had several sheets of paper towels ready to wipe my finger clean. Also have a trash can or bag ready for the used paper towel I would then move on to the next joint. You do have to move quickly as the caulk begins setting quickly. You also have to do this in a well ventilated area as the caulk is quite smelly. I would wear a respirator if you have one. It is an acidic gas that will burn if you breath too much of it.

Once you have the interior joints done, I recommend you seal the exterior joints as well even though you only removed interior silicone. Turn the aquarium upside down and place it on a couple of old boards so that the interior isn’t sealed against the floor. You will need very little for the exterior. Just enough to cover the joints. Smooth it as again as with the interior joints. Remember to do the bottom as well.

Sealing the exterior just makes a mess and won't do much to help IMO and IME. Otherwise, this section looks good

Keep the tank dry and at room temperature for at least a week. Silicone needs time to cure. After a week, test fill it where if it does leak clean up is easy. I did this in my garage. Make sure the tank is on a level surface. A warped or uneven surface will stress the tank causing it to leak and possibly break the glass. Leave the tank sitting with water for at least a week. Sometimes leaks take a while to show up.

If it makes it through all this without leaking completely empty the tank and move it to where you want it. Support it from the bottom while carrying it. You don’t want to stress a joint by holding it on the sides. Again, be sure the surface you finally place it on is very close to level and is even (not warped,) Again this is to avoid stressing the joints. Good luck.

Leaving a week to cure is a bit excessive IMO, but not bad advise. Likewise with water testing 48 hours is the usual curing time for silicone, and IME, any leaks will show within an hour if it's sat on newspaper to show any and all damp

All the best
Rabbut

p.s. diden't proof-read, so I appologise in advance for the many spelling and typo errors in there

 

[kcharley]

Silicone lifting from the glass is either old silicone failing, damage from a sharp object (reptiles generaly don't do that much damage to seals) or just poor prep work Old silicone and silicone comming off due to poor prep werk must be re-done, as it will usualy fail within 6 months of starting to lift... Damaged silicone can be repaired with a "splice"...

Meths are Methelated Spirits, though any alcohol based chemical will work At work, it's Johnson's flea spray... Razor blades are the cheapest tool to work with, and are disposable for when they are blunt after use. I find a disposable craft knife the easiest, but you need safety glasses with those. You are forsing them to flex, and this can lead to them snapping Any sharp tool should be able to remove the silicone without too much trouble

In some cases, when the structural (bits between the glass) silicone has gone, or where the silicone is pealing off due to poor prep work, it is actually advisable to re-seal the lot Test the structural silicone after you have cut out the seams, by pressing outwards on the panes. If they move, you need to strip and start from seporate panes of glass If it does not move, you are correct is saying that the tank should not need stripping completely

Glass should not gouge through silicone removal. If it does, you are using the wrong tool for the job, or the tool you are using has a bust blade You would have to have super human strength to get the glass to break by pressing on the seams, so that's not much to worry about. The pane would pus outwards before the glass brake in that case anyway... It's sudden shocks that do in a pane, not gradually applied pressure

Otherwise, that section is OK

You need an alcohol based cleaner, not just an none-petrolonium based one... Bleach won't do much for grease, and that's a non-petrolonium based cleaner... I'd wipe down a few minuites before actually running the beads I'd apply masking tape after an initial wipe down with your cleaner if you are going for a neat finish, and then I'd wipe down again, leave it for 5min and then start caulking...

Hardware trade silicone contains anti-fungral chemicals to prevent mould, and also has a different solvant base. The latter has questionable risk, but fungisides WILL kill fish

Sealing the exterior just makes a mess and won't do much to help IMO and IME. Otherwise, this section looks good

Leaving a week to cure is a bit excessive IMO, but not bad advise. Likewise with water testing 48 hours is the usual curing time for silicone, and IME, any leaks will show within an hour if it's sat on newspaper to show any and all damp

All the best
Rabbut

p.s. diden't proof-read, so I appologise in advance for the many spelling and typo errors in there

Rabbut,

Thanks for the review. I'll edit to add your comments and forward it to the guy who I am trying to help. I appreciate your sharing your knowledge and experince.

Greg

 

[newb]

thanks everyone, for the great input. I think I am going to keep looking for a tank that is not peeling. Or keep saving my pennies and buy new.