How to reseal a secondhand aquarium - a step by step guide

[@Rickyyy728]

I’ve watched a lot of resealing videos and yours was the most informative! Thank you!

[@freshflowaquatics]

Thank you! I'm really glad I was able to help, good luck with the project!

[@821702feb]

I'm sealing a 135 g this weekend and I now feel comfortable to do it

[@freshflowaquatics]

Glad to have helped. Good luck with the project!

[@jones0662]

With doing this method did the 135 end up holding?

[@MakoyUnggoy]

I'm on my 3rd re-seal but I haven't done one for 20 years so I'm just brushing up again!

[@freshflowaquatics]

I hear you! I only reseal tanks every now and then as well. Good luck with the project!

[@DogTrainerDave94]

@@MakoyUnggoy you got this

[@CA-tk8yn]

The black silicone surprised me. It's a nice touch. I have a used tank I just got and will go with black too. Thanks

[@freshflowaquatics]

Thanks for dropping a line. I love the black silicone, it helps conceal the algae 🤣

[@jjhz83]

You killed it! Great video! You answered all the questions I had.

[@freshflowaquatics]

Hey, thanks for dropping a comment! Glad this video helped you!

[@MarijkeWillemsen990]

I’m amazed at all those bad silicone seals, a lot of tanks seems to have this problem. Also expensive aquariums from 7 years old or so made on the specification of the client. I have always (second hand) aquariums from Juwel, market leader in Europe. My oldest is from 1960. This 65 years old! Still in use, with perfect silicone seals. They have a semi industrial way of manufacturing, processes and cleaning are very good I think. Perhaps that’s why their aquariums last forever.

[@freshflowaquatics]

65 YEARS OLD?!?!?!?! That's absolutely insane. Does it have ametal frame? Some of those antique aquariums are really really cool; I've seen a coupe with some really unique looking designs. I wonder if the silicone was different from today. Things really aren't built to last anymore...

[@TheFishBeast]

Nice video! An alternative is just to Eurobrace the top with some scrap glass since the broken brace won’t provide any structural support.

[@freshflowaquatics]

Thank you and appreciate the tip!

[@theaquaticdesert]

Bravo bravo bravooo 👍🏻👍🏻👍🏻👍🏻 perfectly put!

[@freshflowaquatics]

Thanks so much @theaquaticdesert been enjoying your videos as well! 🍀🐟

[@skapegoatfilms]

i assumed you had to do the bottom as well, since silicone wont stick to silicone, you will have a weak seal where old meets new at the bottom....i did this today and am just taking a break before adding new silicone. taking the bottom off and adding one new seal all the way around seemed like the right thing. didnt wanna worry about that seal constantly

[@freshflowaquatics]

Hope the project went well!

[@GoldshackGarage]

I was just thinking the same thing

[@stoneysscapes7544]

​@@GoldshackGarageThe silicone between all 4 sides connected to the bottom pane looked brand new and the preparation done above was perfect so. the new silicone will not need to stick to the old silicone to make it hold water and like anything we do with tools and labor preparation is the hard part 😎🩵💙

[@CoralReefkid]

Nice video man. I’ll be saving this rare 30 gallon breeder tank now.

[@freshflowaquatics]

Thanks for dropping a comment! Hope the reseal goes well. I only take the time and effort to do this for tanks that are no longer in circulation - unique dimensions.

[@stoneysscapes7544]

​@@freshflowaquaticsI have resealed a few that I got for free from either seeing it on the road or Marketplace and I can agree with the well deserved praise for how you thoroughly covered everything. So i definitely have a quirky one that I have been in no rush to do but I think it's time to get out the tools and Acetone , one question is what if any was the Best silicone you used? Honestly I have been having good results with Aqueon and I have always bought black too. So wish me luck with my Fluval Flex that a few years ago was the 15 gallon before I cracked it when I had a great idea for keeping my Nerite snails from going into the rear chambers. When I placed a piece of twinwall greenhouse that apparently I should have cut little more than I did because a few hours after the left side cracked close to the back corner 🤬 So I decided to make it a one of a kind by cutting both sides exactly the same and the bottom pane as well and then toss the lid. Haven't decided yet if I want to have the back filter or since I am losing more than that after all is ready to go especially since I will be getting some clips for a new glass lid . I'm going to keep track of the gallons but my guess is around 7 - 8 max.. 🧫

[@chucksaduck]

Thanks for the info! Based on your pictures of bad silicone, my used 45gal tank looks to be in really good shape. That is all but about 3 inches that something had scratched at. Can you do a small spot renewal or would the whole seam need to be replaced? What are your thoughts on flexseal tape? Thanks

[@freshflowaquatics]

No problem, glad to help! Generally it's not a good idea to seal just a small segment. I actually did that on my Fluval Flex 15 gallon and it's held for years. That being said, I would be concerned about a larger tank like a 45 gallon... That's a lot more pressure and so much water to end up on your floor 😅. Id do the full seam. I've never used flexseal tape personally, but it's my understanding that it is not aquarium safe due to chemicals that leach into the aquarium.

[@victoriapapesh6892]

Awesome video very easy to understand🎉🎉🎉🎉

[@freshflowaquatics]

Thanks for dropping a comment, glad I could help!

[@Steviemightdoit-cg1su]

good job on this

[@freshflowaquatics]

Thanks, good luck resealing your aquarium.

[@bigdaddydonzella]

Got a used 125 and was disappointed that the seals were looking pretty bad. Feeling like I can fix that now.

[@freshflowaquatics]

That's a good sized tank, sure it'll be a fun project. Good luck!

[@matel9477]

You said you didnt re seal/caulk the bottoms. Any issue with the new silicone adhereing with the old on the bottom because i hear silicone doesnt adhere together?

[@freshflowaquatics]

Great question. It is kinda contradictory how I resealed the tank since I said that silicone doesn't adhere to silicone. I tested the tank in my garage for a couple weeks, and I've had it set up for 2 months with no issues. If you want to be extra safe, you can reseal the bottom as well.

[@KnowingGodExplorers]

Okay but if you don't remove the seal in-between the glass panels the new seal will not bond to them. If you want a tank that you are certain won't leak, don't cut corners... Thanks. FYI have you trusted jesus has your Savior? He is calling you.

[@freshflowaquatics]

@@KnowingGodExplorers You don't have to break a tank down completely to reseal it.

[@polskiklubmiosnikowmieczyk2771]

Good job!!

[@freshflowaquatics]

Thank you!

[@polskiklubmiosnikowmieczyk2771]

@@freshflowaquatics :)

[@anthonynguyen8659]

I’m glad I came across your video! I’m in the same exact situation but with a 75 gallon. I really don’t want to remove the bottom glass seal because it’s in great shape. What do you think? How is yours still holding up?

[@freshflowaquatics]

Hey, thanks for the comment! The tank is still up and running with no issues. The bigger the tank, the more likely I would be to not take any chances and just go ahead and reseal the whole thing. I would probably reseal the bottom for the 75.

[@cski13]

Hey great video just resealed my 125 one of my seams was starting to get a bit tacky as I was working it in it on the bottom it has a rougher surface and slightly bumpy compared to the side seams that are almost perfect is this okay long term ?

[@freshflowaquatics]

Thanks! If you were still able to push down and get the silicone to adhere to the spots it needed to go, then I would imagine you are fine. If it was so tacky that it wasn't able to press against the glass then you'd probably see lots of bubbling and that could be cause for concern, especially with a 125. 🌊

[@KarlPeriard]

You wait 24h before filling it for 7 days or do you wait a little longer to be sure it will be fully cured and thanks for the video its been a nice guide ! I got an other question too i use vinegar instead of acetone to remove the tiny bits that wont budge do you think it can damage the seal between the glass first time resealing a tank thanks for your advise

[@freshflowaquatics]

I'd wait 24-48 hours to let curing finish before adding water. Check the back of your silicone tube out to see what it says. Every company is different, but it's usually 24-48 hours. You can always play it safe and wait an extra day or two, but beyond that I doubt you are getting any extra benefits.

[@lgndfalcon4868]

ill be doing the same to a 220-gallon tank soon. really similar wear it had no leaks but the seams on the corners do need re-sealed. The bottom looks perfect but I'm nervous about not doing the seams and having issues later on .... whats your opinion?

[@freshflowaquatics]

Good question. I would definitely recommend resealing the whole aquarium for a tank that size. In my opinion, it wouldn't be worth the risk! That'd be a lot of water on the floor 😳

[@lgndfalcon4868]

@@freshflowaquatics awesome. Definitely agree

[@toneloke5145]

Great job but I'm still worried about the fact you cracked it, how did you get on with fixing the crack 👍

[@freshflowaquatics]

Thanks! I used a lot of silicone at the top when I put it back on, holds everything together. The brace was already cracked when I started taking it off. This tank had really been through the works 🤣

[@issacabraham6855]

I have an aquarium, there was a small crack on rhe front glass, so I replace it with new one only cutting the silicon on the front side. V have the old tank which is nor made of tempered glass. Still it is leaking from the front side I need your expert ideas.

[@freshflowaquatics]

Hey, sorry to hear that. Such a bummer to put that time in and still have a leak. I suggest that you pull all the glass panels apart and rebuild the aquarium. When you're adding in a new piece of glass that's the safest way to go.

[@fatguywhobreathesfire6488]

So you don’t have to silicone the top right? I’m in the middle of doing a 36 aquian bow front tank and I think it’s going good but I’m scared because I’m in a apartment and not sure where to test the water at I’m on the ground floor but it’s getting cold now and I want to water test as soon as I could when I’m done cleaning the tank out of the old silicone

[@freshflowaquatics]

Are you asking about the break in the brace? I did seal the whole top portion of the tank by laying a thick bead across the top of the tank before putting the brace back on... which is what holds the brace together. Lemme know if I'm missing your point here. To be honest, I used to do this more often and was a little nervous when I filled the tank. I think there is always some element of being nervous until you've done it a few dozen times. If you have a standing shower that is a level and smooth ground, that can be a good place to test if it holds water. Otherwise if you are really in a mind you could try putting a tarp under the tank or even buying a really big plastic tote to put the tank in.

[@freshflowaquatics]

Also your username intrigued me so I checked out your channel. That was awesome!

[@fownine4life853]

I just purchased a 75 gallon acrylic aquarium it started leaking at the very bottom. at the time when I purchased the aquarium I did not realize that silicone does not adhere to acrylic just eyeballing it it looked like Factory but obviously somebody resealed it in the past. long story short I have to take out all of the silicone and go back with acrylic cement

[@freshflowaquatics]

Ahh sorry to hear that. Hopefully the project goes well! I actually bought this tank and stand used without realizing how much work I'd have to put into both

[@marcustorres8309]

Going to seal a 150 gallon soon but my seal issue is opposite the bottom seal is bad

[@freshflowaquatics]

Good luck with the reseal, hope it goes well!

[@marcustorres8309]

@@freshflowaquatics when resealing the bottom is it recommended to do the corner seams they are mint but I'm neverous as heck because the tank is 150 gallons

[@freshflowaquatics]

@@marcustorres8309 Great question. For a 150 gallon tank, I'd be nervous too and would 100% definitely reseal the whole aquarium. That's a ton of pressure in a tank that size.

[@marcustorres8309]

@@freshflowaquatics any brand you recommend for silicone

[@ender003]

When I was removing silicone from the bottom of a 40 gallon, I noticed the razor blade accidentally went between the two panes of glass. Is the process shown in this video still sufficient for keeping it together?

[@freshflowaquatics]

Oh no, I'm sorry to hear that. That's not a good thing to happen, since it can compromise structural integrity. You'll probably want to take all the glass apart and rebuild at this point.

[@shey_of_wander]

So then your new silicone is not adhered to the silicone of the panel seam?

[@freshflowaquatics]

Correct, it is not adhered to the silicone between panels. If you want to do that, you'll need to completely break down the aquarium and rebuild it.

[@pikasgf]

hello, quick question, my silicone looks good for the top but silicone for the bottom has turned orange.. i have let it sit for awhile with just water and nothing else so im wondering if that’s why. but i’m planning on actually using it now but am worried that it may not hold. would u recommend to change the silicone? it’s not receding but the color change it worrying, thoughts??

[@freshflowaquatics]

Hey, great question. It's possible that the silicone has turned a little orange from having algae growing on it, basically resulting in a stain... But that's pretty uncommon. Does the texture of the silicone that is a different color feel the same as the top? Also, how old is this tank?

[@pikasgf]

@@freshflowaquatics yes they feel the same and i’m not completely sure how old it is. i got it from someone on offerup and they didn’t really specify. there was no leakage tho when i went to go pick it up and none when it was filled back at my house.

[@tigercow]

How important is it to remove the top brace?

[@freshflowaquatics]

I've heard conflicting opinions from reputable sources, so I'm not convinced that its absolutely necessary. Mine was kinda damaged when I started, and I ended up cracking it... Being a King of DIY fan, I opted for the way he did it and removed the top brace.

[@tigercow]

@@freshflowaquatics thank you

[@dawnstuart7607]

How long did you wait before putting water in the tank to test it after resealing?

[@freshflowaquatics]

I waited 48 hours to let the silicone dry and cure before the test fill.

[@mr.tvorch]

Why didn't you reseal the bottom silicon? I hear everywhere that silicon doesn't stick to silicon. Your new layer of silicone, may peel off from old one with time, no?

[@freshflowaquatics]

I didn't reseal the bottom because the silicone was still in great condition. I learned to do this from someone years ago and should have talked about it more in the video. Reseal the bottom for the greatest durability. It's not likely to peel, but I suppose water could get in there, granted I feel good about how the shape of the reseal. It has been a little over a year now that it's been filled with water FYI. Good question!

[@GLENN_3310]

thank you 😊

[@freshflowaquatics]

You're welcome, hope it helped!

[@AQUARIUMFREAK123]

i need to use BLACK COLOR SILICONE that must be AQUARIUM SAFE... can black silicone be used as i see you are useing it.

[@freshflowaquatics]

Yes, you can use black silicone. You can find aquarium safe silicone online in black.

[@AQUARIUMFREAK123]

@@freshflowaquatics i bought the GE 100 percent silicone BLACK in HOME DEPOT.. is this ok, it does not say that it has any mold retardent in it.

[@freshflowaquatics]

@@AQUARIUMFREAK123 I've used that before, though the back says it's not aquarium safe. Some people will say use it, others will say don't. If you want to be 100% sure, you can buy a product specifically designed for aquariums.

[@AQUARIUMFREAK123]

@@freshflowaquatics thank you.. when you used it , did you find that it was safe ?

[@freshflowaquatics]

@@AQUARIUMFREAK123 Yes, I've found that it has been safe with my freshwater tanks.

[@hamzakanaan8333]

Why didn't you remove the old silicon?

[@freshflowaquatics]

I did remove silicone.

[@LGmarge]

How did the reseal hold up so far?

[@freshflowaquatics]

Looking good so far. All the water has stayed in the tank!

[@andrepakadr.rofllmao]

Glad I watched a video where SOME ONE told me to take the top frame off.

[@freshflowaquatics]

Thank you! hope it was helpful.

[@stevenkinnison8044]

I just picked up a second hand aquarium and the whole bottom of the tank lt loose.

[@freshflowaquatics]

Definitely make sure to use the same process and reseal the whole tank including the bottom!

[@DogTrainerDave94]

Use a heater all the silicone will come off literally take a space heater put it inside the tank wait 30 minutes wear gloves literally peels off

[@freshflowaquatics]

Thanks for the tip!

[@DogTrainerDave94]

@@freshflowaquatics no problem been stripping tanks since I was a teenager

[@DogTrainerDave94]

@@freshflowaquatics also you can use nylon string like dental floss and cut the silicone out of the crevices with no scratches little trick i learned from my grandfather he was the og fish tank keeper.

[@freshflowaquatics]

@@DogTrainerDave94 Thanks for the tips, I'll have to try them out next time!

[@chevyfish4028]

Please do not recommend this black sealant located on your affiliate link because it contains a 10 year mold inhibitor which is toxic to fish.

[@freshflowaquatics]

Thanks for the comment, but I don't think that there is mold inhibitor in this. Maybe you are thinking of their "10-year mold free" bullet point on the tube? Unfortunately that sort of terminology is confusing because it sounds a lot like mold inhibitor, but it's not the same. You could advertise a glass aquarium as being mold free even though it doesn't have any mold inhibitors. I believe that has to do with the way that the silicone cures and creates a surface that is impenetrable to mold... This is my assumption based on the fact that when you look through the product data or safety sheet there is no mention of mold inhibitor, which you can access here ⬇️ gesealants.com/products/advanced-silicone-2-window-door-sealant/2811093 Here is the list of chemicals found under the information of ingredients section, none of which are mold inhibitors. That being said, if I missed something, please let me know. I'm willing to admit if I've made a mistake and I'd like to know if that's the case. I've used this in the past and currently have tanks with it in it, and livestock are all doing great. Here's the list of ingredients. -Silica, amorphous, fumed, crystal-free -1,1,1,3,3,3-Hexamethyldisilazane -Trimethoxy(methyl)silane -Carbon black -octamethylcyclotetrasiloxane The safest option may be to get silicone that's designed for aquariums... that being said, for all I know they repackage GE silicone just the same way that you can buy super glue from your LFS with its branding on it.

[@diewlaylomei]

why does everyonie use their fucking fingers and not a tool. Makes it look clean and crisp

[@freshflowaquatics]

Lol, it's a personal choice. I enjoy the way it feels using my finger to make the seal. I've cut little tools or jigs out of other materials in the past and find they gunk up and become less effective than my finger. Tool or no tool, I've found tape is the way to get the cleanest lines.

[@Shantytowns]

Why not break it all the way down and completely reseal it? It seems strange to go to all that effort but not completely reseal it?

[@freshflowaquatics]

Good question. I didn't reseal the bottom because the silicone was still in great condition. Strong lighting is often what causes silicone to break down, but since there is substrate along the bottom of the tank the silicone was protected. I should have talked about it more in the video but I wouldn't recommend this approach for very large tanks. I would do what you said, just go ahead and reseal all of the seams.

[@dominicdaniel2242]

😻 P R O M O S M

[@freshflowaquatics]

What you talking about?