# Aquarium safe way to seal PVC pipe?



## Speaker73 (May 1, 2010)

Just use a pvc glue that is potable water safe.


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## AbbeysDad (Apr 13, 2016)

I'd use GE Silicone I (used like adhesive) - a great seal, but could be disassembled if/when desired.


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## Rab1515 (Dec 9, 2016)

Normal PVC cement is fine. Make sure you prime first, ugly if you prime too much but makes sure you have a good weld. If you have never done PVC before twisting quarter turn after inserting each piece helps remove the "rubber banding" effect that the cement has. Keep lots of paper towels on hand to wipe off excess cement and it should turn out ok, the worst that can happen is you have to paint it to cover up the purple stains.


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## DaveK (Jul 10, 2010)

Rab1515 said:


> Normal PVC cement is fine. Make sure you prime first, ugly if you prime too much but makes sure you have a good weld. If you have never done PVC before twisting quarter turn after inserting each piece helps remove the "rubber banding" effect that the cement has. Keep lots of paper towels on hand to wipe off excess cement and it should turn out ok, the worst that can happen is you have to paint it to cover up the purple stains.


Clear PVC primer is available. I find that it works out much better for aquarium projects, since you don't get any purple runs on the work, like you do with normal purple primer. 

The usual purple primer is dyed that way so a building inspector and others can check that it was used in plumbing for construction projects.


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## lksdrinker (Feb 12, 2014)

Speaker73 said:


> Just use a pvc glue that is potable water safe.





AbbeysDad said:


> I'd use GE Silicone I (used like adhesive) - a great seal, but could be disassembled if/when desired.





Rab1515 said:


> Normal PVC cement is fine. Make sure you prime first, ugly if you prime too much but makes sure you have a good weld. If you have never done PVC before twisting quarter turn after inserting each piece helps remove the "rubber banding" effect that the cement has. Keep lots of paper towels on hand to wipe off excess cement and it should turn out ok, the worst that can happen is you have to paint it to cover up the purple stains.





DaveK said:


> Clear PVC primer is available. I find that it works out much better for aquarium projects, since you don't get any purple runs on the work, like you do with normal purple primer.
> 
> The usual purple primer is dyed that way so a building inspector and others can check that it was used in plumbing for construction projects.


Yup, regular pvc cement/glue is perfectly fine. No need to use silicone as its not really intended to weld pvc together. Same reason why acrylic tanks dont use silicone at the seams. 

I've been told recently by a few different people (who I'd consider knowledgeable on this) that the primer is really not necessary at all. Yes its necessary to meet code for certain plumbing aspects; but so long as the pvc pipe is relatively clean you should get a perfect bond without using the primer. 

Unless the OP is asking about trying to glue it up under water? In that case, I'd say no.


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## Speaker73 (May 1, 2010)

I've never used primer before with my pvc projects and have never had a leak


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## sdwindansea (Oct 28, 2016)

Speaker73 said:


> I've never used primer before with my pvc projects and have never had a leak


Primer will provide a much better seal with PVC. It is really only needed when the "plumbing" is under pressure. If it is just for a constant flow of fluid it probably will not make a difference.  However, when pressure builds up (e.g. a closed faucet) then you will definitely want to use it.


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## Speaker73 (May 1, 2010)

So just a fyi. I did a pvc UG filter for a shrimp tank that did well but there way always some mulm at the bottom of the tank that never cleared. It's almost impossible to clean everything out due to the water flow


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## deeda (Jun 28, 2005)

You don't need to glue or seal PVC connections if they are submerged in the tank such as in your picture in the 1st post.


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## DaveK (Jul 10, 2010)

lksdrinker said:


> ...
> I've been told recently by a few different people (who I'd consider knowledgeable on this) that the primer is really not necessary at all. Yes its necessary to meet code for certain plumbing aspects; but so long as the pvc pipe is relatively clean you should get a perfect bond without using the primer. ...





Speaker73 said:


> I've never used primer before with my pvc projects and have never had a leak


I though this too, until I had a check valve pop out of the fitting on one end, causing a flood. Just using the PVC cement alone might work. It might even work most of the time. However, I learned from experience that it doesn't work all the time. 

Using PVC primer is cheep insurance. for the little bit of extra work, your sure you have a good joint. This really isn't the place to skimp, especially if you have to explain the flood to a spouse or landlord.


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