Plumbing... toxicity? PVC/solvent compatibility   3/12/08 Hello Crew, I recently plumbed a sump/refugium below my tank. I primed and cemented <Solvented...> everything with Oatey Purple Primer and All Purpose Cement. On the first day I made the U-tube for the return and hung the overflow working my way down. On day two I finished my drain line, hung my U-tube and finished the return. I let everything sit overnight and started everything up the next day after work. <Good to be methodical here> Everything worked great, there were no leaks, it was beautiful. I sat there for the longest time staring at it, feeling like I really accomplished something. Everything looked fine before I left for work the next morning. When I returned, however, I returned to a horrible chemical smell, and found all of my fish on their sides breathing rapidly. Not like the cement smells, it was much worse. I acted quickly with carbon, water changes, and disconnected all of my plumbing. I only lost a Six Line Wrasse. All of the difficult fish and corals unbelievably made it through. After disconnecting the pipes, which we re PVC by the way, I was sure that that was the source by the smell. I let the pipes dry for a day. Then I filled the bath tub with vinegar and warm water, letting it sit overnight. The next day I ran warm tap water through them and the past two days they've been drying out. The problem is that they smell like cement again and I'm a little scared to try them now. When I hung my U-tube <... what is this made of? Are you sure it's PVC?> the end was submerged in my display, so I'm not sure if that may have kept the fumes in the pipe and effected the curing or what really caused this. So my question is, do you think it is safe to try this again? I may have mixed a little of the primer with the cement while it was still wet, <Mmm, this is not the protocol of using these products (yes, there's even instructions, plumbing code outline for solventing, priming plastic pipe!)... See the cans' instructions> but at the time I didn't think it would matter. Now I don't really know where I went wrong. Retracing my steps, that's about all that I can think of. The bottle recommended two hours of curing time, which it had and then some. I was just about to buy all new parts, so I could start from scratch, but I figured I would see what you guys think first. Thanks for taking the time to answer my long-winded question, I just wanted to be descriptive for all who read this. Thanks, Jeff <Jeff... do please send along a pic or two... Esp. of the U-tube... is this polyvinyl chloride? Bob Fenner> Re: plumbing, PVC solvent smell, issue  – 03/13/08 I am sure the U-tube is PVC. <Yes... I see this in your excellent photographs> I made it out of 90 degree elbows and short lengths of PVC pipe. It was just a starting point for plumbing my return. When I said I may have mixed the primer with the cement/solvent (bottle says cement), <I do understand, agree... Will try to explain. Cements imply that "something" is left/making the "joint" twixt surfaces... My point/intent is to state that these materials actually act as solvents... melting the PVC together...> I meant that after applying the cement I noticed the applicator was a little purple. <Which is okay... is colored to help/make sure that the applicator (you, I) know where and that we have applied it... there are color-less primers that some commercial folks use... and many friends/associates who are disdainful of using primer at all (I'm not one of them)... Relying on the cleanliness, new-ness of the pipe, fittings, and the solvent/cement to make the joints alone> I did allow time for the primer to dry, but maybe a drop rolled to the bottom and went unnoticed. <Shouldn't be an issue> I don't know for sure. I did not deliberately mix the two. I also thought it may have just been a result of the cement/solvent reacting with the now purple PVC. I am new to plumbing, but I did try to follow the instructions on the bottle. I will probably use the green "Heavy Duty" type solvent next time to avoid this problem all together. <Agreed... I do use a bunch of this... or the Christy's "Super Hot Blue" solvent... in dirty, wet applications... instead of the thinner, clear or grey products.> Here are the pictures that you requested. It's not much to look at in the tub, but it looks good when it's set up. Thanks, Jeff <Looks like a good job... And, really, there should be little to no residual smell... and no dangerous chemical activity/reactions once the joints are an hour or more old, air-exposed... I would rinse them in freshwater, and use at this point. Cheers, Bob Fenner>

Super Glue or PVC Solvent? - 06/30/07
Hi Folks,
<<Hello>>
I am uncertain whether I can or must use PVC compound to secure fittings or whether Super Glue (cyanoag) works as well???
<<Trust me here my friend...use a proper PVC cleaner and solvent. EricR>>

Can I Use Epoxy To Patch PVC Leaks? – 06/07/07
Hi guys! Jason here from Manila.
<<Greetings Jason...Eric from SC here>>
Hope you are having fun.
<<I’m breathing at least...>>
I'm done PVC cementing my pipes, and will be checking for leaks soon enough.
<<Okay>>
If I have a particular piping structure that I do not want to rebuild from scratch because it has a leak,
<<May not have a choice here>>
what are my other alternatives to patch the leak?
<<None really...is always best to cut-out/replace the offending connection>>
Will using epoxy glue be sufficient to patch a leak permanently?
<<Likely not, in my opinion. You could try swabbing or injecting some PVC cement at the leak but this rarely works, especially for the long-term. But no need to “rebuild from scratch,” (you did plan/allow for this by leaving a bit of extra pipe length between the joints?), just cut out/replace the leaky bit and leave the rest be>>
Also, I'm thinking of getting a TR15 Teco chiller for my 90 gallon tank - I've discussed via email about the flow-rates for the chiller with some Teco technicians.. they assured me that there is no efficiency loss as long as I am running the chiller with a pump who's
flow rate is from 100 to 790 gallons.
<<I saw these units at the IMAC in Chicago this past weekend...appeared very well made, quiet, and efficient units>>
I was thinking of running my Eheim 1260 (635 gallons) thru my chiller and back up to my display as my return pump.
<<This is how my chiller is plumbed>>
Should I get a smaller pump?
<<I see no reason to, no>>
Thanks,
Jason
<<Happy to share. EricR>>

Connecting Overflow PVC with Silicone Only?   5/20/07
Hello Crew!  Jason here from Manila.  Hope all is well with you.
<Yes my friend, thank you>
I've read on your FAQs how you support using silicone (vs. cement) on threaded PVC fittings, as you can easily pull it out when you wish.
<Yes... make a nice, cushioned seat...>
I have PVC going out of my overflow bulkheads, that I would like to use Silicone (vs. cement) as I will have an extremely difficult time removing it if the pieces are cemented together.
<Yes... have to be cut, replaced if solvented...>
I am not able to get threaded fittings, unless I make my tubing bulky with extra PVC pieces (which I do not want to do if I can help it).  So I have slip PVC pieces.  Can silicone provide a proper seal on slip PVC pieces?
<Mmm, no... too likely these joints will pull apart>
I am not running any pumps thru these.
The water running thru here is from my overflow, into my sump.
Hope you guys can help!
Jason
<Perhaps looking for, using "unions" (a type of re-joinable PVC fitting) will work out better for you here. Bob Fenner>

Is Silicone the Savior for Sealing?  ...Mmm, Depends On the Application - 04/27/07
Hi Guys, Jason here from Manila.
<<Greetings Jason...Eric here from warm and muggy South Carolina>>
I've read your FAQs and noted how you guys like to use just silicone on threaded PVC to make a nice seal.
<<Many do, yes...but I prefer Teflon tape for this>>
And it can be undone, unlike PVC solvent.
<<Yes...but then, it doesn't make any sense to me to use threaded fittings if you plan to use solvent glue>>
I'm making my closed-loop circulation, and I've used PVC solvent on the slip joints.
<<As you should...>>
If I find a leak in one of the joints, can I seal it with a dab of silicone, or must I start over and recreate everything.
<<If a solvent-welded joint begins to leak you are better off cutting it out/replacing the joint altogether.  The silicone does not really "adhere" to the PVC and even though it may stop the leak temporarily...it will eventually fail>>
I've got to recreate everything, because I can't just "undo" PVC solvent.
<<Correct>>
Also, can I use just silicone on PVC slip joints, out of water?
<<Nope...need to be solvent welded>>
My other question involves bulkheads.  My buddy here uses bulkheads from the local hardware store, female and male joint.  No gaskets, just silicone smeared on the joints, and on both sides of the glass to provide as the gasket.
<<I see>>
Is this a good sealed joint, or do you guys suggest gaskets?
<<I prefer to use a gasket (provided with the bulkheads I purchase)>>
If so, what kind, and on both sides?
<<An EPDM rubber or neoprene gasket should suffice.  I place the single gasket under the flange on the wet side of the bulkhead and use a smear of silicone on the dry side to seat the nut>>
Thanks!
Jason
<<A pleasure to share.  Eric Russell>>

Tank Plumbing...Pipe Diameter/Joint Sealing - 04/02/07
Hi Guys!
<<Hello Jason>>
I am building a closed-system with SCWD for circulation after reading many of your FAQs and articles.
<<Hmm...I think you mean a "closed-loop">>
You guys are great!
<<Glad you think so>>
I hope you can help with some plumbing questions that I tried searching for on your FAQs.
<<I shall try>>
I may be getting an Eheim pump...  If the output valve is 3/4", after reading your FAQs, you've said the piping should be a bit bigger.  Will 1" piping be fine for a 3/4" valve?
<<It will>>
I also read that you guys suggest flexible hose piping to the valves to reduce vibration.
<<Yes>>
Can I just use a clamp with your suggested silicone on the valves?
<<You can, yes...but if you are using the pump in a "submerged" fashion I don't feel you need the silicone>>
When connecting joints that slip, is it fine just to use Silicone to create a seal .. or must I use PVC solvent?
<<Use PVC solvent.  Done correctly this will make a permanent watertight seal, and if you make a mistake...is cheap to "redo">>
Seems to me that if joints are threaded together, you suggest silicone.
<<Ah yes, for "threaded" PVC joints the silicone will do fine...and also allow the connections to be undone when/if necessary.  Though personally, with the exception of seating/sealing bulkhead fittings, I prefer to use Teflon tape for threaded joints...is quick and easy to apply/reapply with no waiting for silicone to cure>>
Thanks guys!
Jason
<<Happy to share.  EricR>>

PVC Glues, actually solvents...   - 02/22/07
Hello again and sorry for being such a pest, but, I live 40 minutes away from the nearest half decent aquatic store, work weekends and have school on the weekdays.  
<No worries!  Always time for the hobby right?>
Anyway... I have been constructing a framework for the rocks in my reef tank using pvc pipe and was wandering if it is safe to use a pvc pipe adhesive?
<My understanding is if it's safe for drinking water it should be safe for the fish tank.  I generally use the purple stuff ...that is the technical name right?>
The one which I have contains Bisphenol a-epichlorohydrin epoxy resin.
<I'm not familiar, looked it up on the net and I'm still not familiar, but if it is used for tap water, it should be OK.>
I don't want to poison my fish but I also don't want to have my rocks collapse and fall through the glass....
<Both bad scenarios, though one is less messy!>
Thank you once again.
<Any time!  -Mich>
Will

Plumbing Glue - 12/28/06
When plumbing a tank, is it all right to use regular PVC glue like that used for plumbing homes?
Thanks,
Ellen
<<Yes indeed, it is quite safe for your wet pets.  Do let the joints "cure" for a bit before running water through them...I find about 15 minutes to be sufficient.  EricR>><RMF likes to let cure for a day...>

PVC Glue "run" time   6/13/06
Quick question regarding "dry time" for PVC solvent:
You stated:
"Oh, and waiting a good hour before running water in newly solvented lines is about right in terms of curing time. Okay?"
I notice fumes that are really overpowering and have been giving my fittings DAYS for the smell to go away. Is this not harmful to the aquarium? Or am I missing something?
<Can be, could be... though I suspect the "after smell" is largely psychological>
I most certainly would love to be able to use the new fittings sooner than later.
Thanks...
            Bruce Webster
<There is a wide-range in PVC "solvents"... cure times... I am a big fan of "Christy's Super Hot Blue", and Green (heavy-bodied) "Landscaper" solvents... but many, likely most folks use clear, lower viscosity Weld-On... with (hopefully) or w/o their "purple" primer (comes in clear as well, but the purple is nice to assure you've applied it). When, where in doubt, I would wait for actual use of solvented plumbing, but do read the manufacturer's recommendation posted on the container. Bob Fenner, who for many years, waited about an hour for up to 2 inch pipe, fittings... >

Liquid Teflon
I recently put a sump together with food grade pails and PVC piping and have spent the last week trying to stop leaks. Finally, I used Oatey's Great White pipe joint compound with Teflon, replacing the Teflon tape, and seems to have done the job. It is supposed to be non-toxic and non-separating, but it does not dry or harden, and has a strong smell.  It lists hydrocarbon oils as an ingredient.  I have used on 3 joints out of many, and theoretically the water will have very little or no contact with the paste.  The total system including sumps holds about 300 gallons of water (net of fish, rock and corals). How concerned concerned should I be about contamination?
Thanks a lot,
Ron
<I would NOT use/trust this material on biological systems. Instead, if there's a possibility of draining, drying all joints, try a smear of 100% silicone sealant (any color, just sans the mildewcides for tub/sink applications) on both sides of threads and gaskets... and allow a day or so to cure. Bob Fenner>

PVC glue
Hi All,
Quick plumbing question.  Is there a major difference using the 2 part primer and cement for gluing PVC plumbing, or can I just use "Christy's" PVC cement which is a purple one part cement that doesn't require the primer??  Also, maybe a silly question, but I imagine once it dries, this cement is non-toxic, correct?? There is no way to apply without getting some that will be exposed to water. Thanks.
<No, no major difference. Make sure you clean pipe ends and fittings well. Yes, it actually welds the pipe together. Apply a  thin coat evenly to each part and twist when assembling, hold together for about a minute to prevent the reaction of the glue from forcing the joint apart. Wipe out as much excess glue as possible. Let cure 24 hours with plenty ventilation. Should be fine after that. Craig>

Sealing joint material choices
I'm planning to replace the hoses on my trickle filter to pvc pipes. what is  the best kind of bond materials would you recommend, to seal the joints  together? 
>>
PVC to PVC, weld-on solvents (light bodied) up to 2" diameter... if the pipe isn't new, clean, do use a "purple" colored primer to clean them up ahead of time. PVC to flexible? Threaded to barbed connectors and doubled nylon snap clamps...
Bob Fenner

Plumbing
I want to hard plumb my filter system. Does it matter what type of pipes I use? Will the glue that you use to put the pipes together harm the fish? Also, what type of UV filter would you recommend for 100 gallon tank? Thank You!
<See the "Plumbing" pieces on the Marine and Pond Indexes on our website: www.WetWebMedia.com... most folks use PVC or ABS of the various formulations used... and the solvents have no effect as they're "gone" when the plumbing is in use... some slight toxicity from these plastics, no big deal. UVs are also covered on the FAQs section of the same name on the WWM site. Happy reading. Bob Fenner>