Page 1 of 1
Attaching hardscape above the waterline in a stocked tank
Posted: Tue Apr 02, 2024 7:31 pm
by BadgersSong
Just got my waterfall up and running, and it's a blast. Now I need to tweak the flow by adding some fake rocks to direct the water where I want it. Problem is, I've got live fish in the tank, and that complicates things. I'm trying to figure out the best way to glue these rocks in place without causing any issues. If you're familiar with this sort of thing, take a look at the details below and let me know what you think.
Some info:
The waterfall pump is off, so the glue won't be exposed to the fish or their water until it's cured. It'll be in the tank, but a few inches above the water line. The shelf is wide, so there's no chance of the glue coming into contact with the water. I'll only be using a small amount: two beads, about 3-4" long.
Aquarium silicone would be perfect, but I'm a bit worried about the acetic acid vapors while it cures. I could use a fan to speed up the process, and the amount of acid that might get into the water would be tiny. Still, I'm uneasy about using it near live fish. My head says it'll be fine, but my gut's not convinced.
Epoxy's probably not an option, since it seems to release some weird gases.
Gel cyanoacrylate might be my best bet. I've used it before with good results. But it's not ideal for this job, since it's just an adhesive and not great for filling gaps or sealing.
Not sure if I'm explaining this right, but I'd love to hear your thoughts, @willie32 @graye and @Avalon - you've worked with this kind of stuff before.
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Tue Apr 02, 2024 10:19 pm
by coltin
Decisions, decisions. I've narrowed it down to superglue or aquarium silicone. The silicone would be ideal - it's perfect for making seals and all that jazz. But, I'm still a bit uneasy about those acetic acid vapors. I mean, I could throw a fan on it, and the amount that actually makes it into the water would be tiny. But, my gut's still doing flips about it.
Superglue's probably my safer bet. I've used it a bunch before, and it's always worked out alright. It's not perfect for the job, though - it's strictly adhesive, so it's not exactly what I need for filling gaps and sealing. But, it's better than epoxy, right? I mean, epoxy's just a no-go with all the weird fumes it gives off.
What do you guys think? Am I overthinking this, or is my gut right to be uneasy?
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Tue Apr 02, 2024 10:29 pm
by Bisco
I agree with coltin's suggestion of using superglue or silicone. There are different types of silicone to consider - solvent-based options like those with acetone, or hot-melt alternatives. The hot-melt type has some benefits, such as curing quickly and producing no fumes, but it does require an impeccably clean and dry surface to adhere properly. It also doesn't bond as strongly as other options, which might limit its uses. However, it could be useful for sealing gaps or voids. If you prefer to use regular silicone, you might want to lower the water level slightly and wait for it to cure to minimize any risks.
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Wed Apr 03, 2024 1:15 am
by BadgersSong
I took the plunge and went with the silicone, and now I'm having second thoughts - but as the saying goes, the die has been cast.
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Wed Apr 03, 2024 1:45 am
by bettaMagenta
If you've got a lid on your tank, I'd crack it open while the silicone cures, just to be on the safe side.
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Wed Apr 03, 2024 1:54 am
by adapros
I recall that you can get CA with a body or you can add it yourself, like glass beads, to help with filling gaps, which might make it more suitable for this application.
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Wed Apr 03, 2024 2:33 am
by Avalon
BadgersSong wrote: ↑Tue Apr 02, 2024 7:31 pm
Just got my waterfall up and running, and it's a blast. Now I need to tweak the flow by adding some fake rocks to direct the water where I want it. Problem is, I've got live fish in the tank, and that complicates things. I'm trying to figure out the best way to glue these rocks in place without causing any issues. If you're familiar with this sort of thing, take a look at the details below and let me know what you think.
Some info:
The waterfall pump is off, so the glue won't be exposed to the fish or their water until it's cured. It'll be in the tank, but a few inches above the water line. The shelf is wide, so there's no chance of the glue coming into contact with the water. I'll only be using a small amount: two beads, about 3-4" long.
Aquarium silicone would be perfect, but I'm a bit worried about the acetic acid vapors while it cures. I could use a fan to speed up the process, and the amount of acid that might get into the water would be tiny. Still, I'm uneasy about using it near live fish. My head says it'll be fine, but my gut's not convinced.
Epoxy's probably not an option, since it seems to release some weird gases.
Gel cyanoacrylate might be my best bet. I've used it before with good results. But it's not ideal for this job, since it's just an adhesive and not great for filling gaps or sealing.
Not sure if I'm explaining this right, but I'd love to hear your thoughts, @willie32 @graye and @Avalon - you've worked with this kind of stuff before.
I'm wondering about your tank size and the height of the areas you need to fill - how do they compare to the overall tank height. One possible solution could be to temporarily lower the water level for a week, allowing the silicone to dry out of water. I'd advise against letting silicone set underwater with fish, as the acetic acid is a concern.
I've had experiences with super glue, and it crystallizes so fast underwater that its long-term adhesion is almost ineffective. However, you could lower the water level, use super glue out of the water, let it set, and then refill the tank.
Another option, depending on the gap size, is pond expanding foam, which is safe for aquatic creatures soon after it sets. I'm a bit rusty on the cure time, but if you go this route, I'd suggest applying it with the water level lowered, letting it set, and then refilling.
Apologies for the delayed response - I've been preoccupied with some furry housemates, so I haven't been on the forum much lately.
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Wed Apr 03, 2024 2:33 am
by Avalon
I'm running on fumes before work, forgive me, I'm pretty sure this is your 55-gallon tank we're talking about, right?
Re: Attaching hardscape above the waterline in a stocked tank
Posted: Wed Apr 03, 2024 6:55 am
by Avalon
Glad I stumbled upon this thread, didn't get a notification about the mention. Thankfully, it sounds like the silicone worked out well for you in the end.