PVC question

jeremy242 · Post by **jeremy242** » 27 Mar 2006, 05:56

I have just gotten toegther all of the things i will need for a river set up and i was wondering what i needed to do to the pvc before it goes into the tank, washing i will do. Also i read that you are able to use sylicone form home depot but it has to be the 100% sylicone, but i picked up one of the tubes of it and it said not to use it for aquariums... any help there. I have also heard the you can use crazy glue as well and it is non toxic. Basically i need to figure out how to prep the pvc and how to stick it together without indangering my fish. Any help or suggestions would be great thanks.

natefrog · Post by **natefrog** » 27 Mar 2006, 10:27

A river set-up is a great idea. There are a number of threads dealing with their set-up and plumbing requirements if you do a forum search.

How I would handle the glueing aspect, (and I do have some plumbing experience), is: First rough up both contact surfaces with a light grade sandpaper, then blow of the dust. Apply pvc cement to both male and female parts of fitting to just past their contact points. Allow to dry. If you are worried about the toxicicty of the pvc cement you can apply a proper aquarium grade silicone found at most LFS, over the cement joints once they are dry, but the stuff does not disolve so i can't see it being an issue.

Words of warning---1.Do a dry fit of the plumbing system before you start cementing them together, (the stuff cures and sets very quickly. 2.Only use pvc cement in a well vented area, (this stuff is nasty until it has cured and the vapors produced have dispursed).

FuglyDragon · Post by **FuglyDragon** » 27 Mar 2006, 11:11

As its going to be inside the tank and minor leaks are of no real problem I just press fit it together, then you don't have to worry about any glue having an effect on fish

MatsP · Post by **MatsP** » 27 Mar 2006, 12:21

Whilst I agree (and like) with the simple and effective idea of FuglyDragon, here's an alternative.

I'd say that if you go to <insert favourite DIY shop> and get the glue that is intended for "Solvent fit" PVC for drinking water, as used frequently in the US, I'd say it's fine to go into aquariums - I think you need two types of stuff, one being a primer and the other a bonding compound [or some such - I haven't actually done it myself in the US, but I helped a friend of mine to get some water pipes fixed at his farm, and that's how I know a little bit about it].

It's suitable for human drinking water, so assuming you flush it through properly after you've put the pipes together, you should be fine. One thougth would be to set up the water flow system in your bath-tub [or other suitable tub] and run it through before you install it in the tank - that way you can run through some fresh water before it goes in the tank.

If you want silicone for aquatic use, you need the ones that don't have any extra additives, which you can get from aquatic shops [for the amount you need, I wouldn't worry too much about the cost differential, but it's probably going to end up at $10-20 per tube] - but it's probably not going to work quite as well with PVC as it does with glass, so I'd say the solvent "glue" method is better for the pipework.

There is of course an advantage (above the simplicity and cost reduction) of NOT sticking the pipes together permanently, and that is that you can take them apart and clean them out.

You may also be able to find "compression fit" pipework in the US - I don't know, since I haven't actually tried to buy that in the US, but if you do, it should work fine with no leaks, and be possible to disassemble for cleaning and maintenance purposes.

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Mats

pleco_breeder · Post by **pleco_breeder** » 27 Mar 2006, 18:39

Jeremy,

I don't intend to argue with the other posters, but if you are going to glue the fittings definitely let them cure at least 2 days. While I was growing up, I did a lot of plumbing work with my dad because I could help by fitting into tight crawl spaces. About 15 years ago, I built my first central filter system for my mom's pet shop. It took about 2 weeks to cut and fit everything, but the returns were the last thing to go together. Since all the fish from the shop were stored in tanks at home, we rushed and moved them to the shop the following morning so they could acclimate to the system before the shop opened the next day. When we opened the door the next morning, we immediately smelled PVC glue. Once we got over to check the tanks, we found most of the fish were dead. After looking at the fish, I was convinced that the solvents in the glue had eaten their gills away as there were very few if any rakers left. It was an expensive lesson to learn.

I've since built a lot of systems, and did it professionally for a while. I never add water or fish till the last fitting has cured for a week. Losing that many fish is a learning experience that you don't soon get past.

Larry Vires

MatsP · Post by **MatsP** » 27 Mar 2006, 19:30

Larry,

Thanks for pointing that out. I don't see that as arguing, but rather as "pointing out something missing from previously given information", which makes the original information given more useful.

I'll try to remember to include information about making sure the solvent weld has cured properly before using the pipes - 2 days to a week seems like a reasonable amount.

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Mats

jeremy242 · Post by **jeremy242** » 27 Mar 2006, 20:23

thanks for all of the help with this. I was able to get everything together without the use of glue or sylicone so i don't have to worry about that. I just did a little customizing of the powerhead and the pipe and i got it to go toeghter nicely. Now i just have to wait for the water to be turned back on to fill the tank back up. I clean the tank on mondays so i fugured i would install it today. It would be my luck that there is a main water line break today after i had drained the water. thankfully the water level is just high enough to run the filter it is just really loud with the water dropping down to the surface. Hopefuly it is fixed soon. Thanks again.