Mating aquarium pumps to standard plumbing.

[Abalone joe]

I'm new to salt water and I'm preparing to dive in. While I've discussed a lot of saltwater issues and read a lot about the salt water side of the hobby; I have found no info on how and what to use to attach the different pumps to the standard types of pvc plumbing. I've used pvc extensively in freshwater setups but never with power water pumps. I'm open to hearing about slip unions, ball valves, bulkhead fittings, head related issues and the like but I already understand those things minus a couple of details. My not understanding the attachment of pumps to the pvc is my major hang-up. Until I understand this I can't design my plumbing systems as their efficiency will ultimately depend on the pump interface.
Thanks in advance for any insights you can offer.

 

[mpomfret]

I'm not real sure what info you want here but I'll take a stab at it. My Mag 7 sits in my sump and has 1/2" NPT on input and output. I wanted to be able to adjust and shut off the flow to the main tank which meant feeding the output into a T and putting ball valves on the return line to the tank and on a line coming back to the sump from the other side of the T. I also wanted to use flex tubing for as much of it as I could, so that meant barb connections to the PVC. I decided on 3/4 tubing and pipe since the I.D. on a 1/2" ball is a bit smaller than 1/2" and I didn't want the added restriction.

With all that in mind and a rough sketch of what gets connected where I went to Home Depot and played Tinker Toys dry-fitting the plumbing parts together until I had what I thought I wanted. You get some funny looks sitting there in the aisle with a lap full of parts trying to piece them together but so what ?

Matt

 

[jmccalip]

<a href=showthread.php?s=&postid=6961317#post6961317 target=_blank>Originally posted</a> by mpomfret
You get some funny looks sitting there in the aisle with a lap full of parts trying to piece them together but so what ?

Matt

You get even weirder looks/comments when you're 15 years old. :lol:

 

[Godoftheseas]

Yeah i can vouge for that i am 16 and just went yesterday to lowes with my overflow box trying to plumb that and my closed loop. All together i spent 16 bucks on pvc which in pvc terms is alot of stuff, it was great i must have gotten asked what i was doing by like 7 people.

 

[Abalone joe]

<a href=showthread.php?s=&postid=6961317#post6961317 target=_blank>Originally posted</a> by mpomfret
My Mag 7 sits in my sump and has 1/2" NPT on input and output.

Matt

What is the 1/2" NPT? Also why do you use T's? Are they a Syphon break? My main question in the beginning was what to use as the interface between the plumbing and the pump itself.
Thanks

 

[sjm817]

BTW, you should double the outlet size on a Mag pump. Mag7 should have 1" plumbing.

 

[coolfish5]

NPT is national pipe thread.

Basically the threaded connectors you can get in the plumbing department will fit the threads on the pump.

So in the mag drive example. The pump has 1/2" male NPT threaded outlet. You need a 1/2" female threaded to slip adapter to hook it to the pvc pipe.

It is recomended at least with the mag pumps to step the pipe size up 2x the outlet diameter so 1" would be the recomended plumbing size.

I'd suspect you can get a 1/2" FNPT to 1" adapter, but I usualy do like the other guys and just test fit till I get what looks like it'll work.

John

 

[mpomfret]

I didn't know about the recommendation to double the outlet diameter. Oh well, I'll fix it some day if it looks like I need to.....

Abalone,

The T is not a syphon break. The pipe from the pump output goes to a T which splits the flow into 2 paths: one to the main tank and one back to the sump. With a ball valve on each branch of the T, I can adjust the flow to the main tank all the way from zero to full blast. You could do it with a single valve in the line going to the main tank and no T but I thought that might wear out the pump faster.

A syphon break need to go near the highest point in the return line. I made one by drilling a small hole just above the water line in the back of the fitting at the end of the return line. That way if the pump fails and the return line starts a syphon the hole will immediately suck some air and break the syphon.

Matt

 

[schristi69]

The connection from the pump to the plumbing depends on the pump you are using. Mag drive pumps are threaded for NPT which means a threaded PVC adapter will screw right in. Pumps like Eheim and Hydor have their own pain in the butt systems. They have inlets and outlets that are threaded...BUT only their adapters will seal properly. They have a rubber o-ring on the adapter that seals against a flange in the housing. So, with these pumps you have to do a flexible tubing to PVC connection using thier tubing inlet/outlet adapters. Eheim does have a pipe adapter forthe outlet side for things like fountain heads and such, but I have not tried it since their parts are so hard to find. Do not trust the tubing connectors on these pumpts!!!! You slide on the tubing to the nipple and then there is a nut that is supposed to tighten and compress the hose against the nipple. This has come off of my Hydor MANY times. Same situation with my Eheim canister filter. remove these nuts and use zip ties or non metal clamps. Eheim and Hydor...good pumps, quiet, low power use but a pain to plumb. Mag drives...run hot, use more power but very easy to plumb.

 

[sjm817]

You can use standard 3/4" MPT fittings in an Eheim 1260/1262. Not sure what size the 1250 is. They screw right in. Wrap it with a few winds of Teflon and you are good to go.

 

[hyperfocal]

<a href=showthread.php?s=&postid=6970914#post6970914 target=_blank>Originally posted</a> by sjm817
You can use standard 3/4" MPT fittings in an Eheim 1260/1262. Not sure what size the 1250 is. They screw right in. Wrap it with a few winds of Teflon and you are good to go.

The pressure side of the Eheim 1250 *isn't* 1/2", it is closer to 3/8" (it's metric, not NPT). 1/2" NPT is too large to fit. The listing on places like Marine Depot and Eheim's own web site are incorrect; I know, I just bought one

I've ended up plumbing mine using reinfoced hose connecting the included Eheim hosebarb to a 3/8" hosebarb - 3/4" NPT fitting, which then connects to a 3/4" NPT - 1" slip PVC fitting. A pain, but nothing too bad.

 

[wiggie89]

basically if you dont understand what npt means it is a female or male threade pvc that changes into slip pvc

 

[bassnman11]

Npt is national pipe thread, either male or female. Slip pvc adapters are available both ways.