head loss question

[rotccapt]

hi all i am working on my 120 gallon plywood tank right now my plan and is currently set up was to use a quiet one 4000 pump(it has a 1" outlet and at my current head of 5 feet it is supposed to put out 600 gph) i chose to use 1" flexibly reinforced tubing for my return that is feeding two outlets one at the top of the tank and one is at the bottom feeding UGJ's. the plumbing is routed so that the line from the pump goes to the top of the tank and hits a "T" that then goes through a ball valve and to a 90* elbow to the top outlet. the other side of the "T" goes to a 90* elbow and down to the bottom of the tank to another elbow and into my UGJ's. everything runs great except the top outlet does not get very much flow just enough to dribble out and make a bunch of gurgling noise. the UGJ's have five 3/4" outlets that have been pinched down to make a nossle. the jets get about 3 inch founties out of them. so my question is what could be causing my top outlet to get no flow? also how much pressuer loss do you think i am loosing through the barb fittings. the barb fittings drop the pipe diameter down to 3/4" from 1".

i am toying with getting and setting up a pvc return pipe the uses two electrical conduite 90* elbows ( the ones that are radiesced insted of sharp bends) do you think this will give be better flow? do you think my ball valve is hurtting my top outlet?

 

[Egon]

Your pump just isn't strong enough to run both. The reason the top, upper jet is not flowing and the lower jets are flowing is head pressure is much lower for the bottom jets so all the water flows out there instead of the upper jet.
1) I would use two separate pumps for your system.
2) If you don't want to use two separate pumps use the ball valve on the lower jets and close that off until you get the flow you desire on the upper jet.

Every one of your 90 degree bends sucks up head loss on your system. Try to minimize bends and you will increase efficiency of your system.

 

[knifegill]

head loss question

[YT]<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/SnJt9p-sHho&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/SnJt9p-sHho&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>[/YT] There can only be one.

 

[rotccapt]

ok that is what i was thinking do you think getting rid of the barb fittings will help?

also could i just not use the top outlet just leave the ball valve open enough to work as a siphon break. my overflow goes through a wet dry tower and then into a sump so i think my water will get plenty of agitation.

last would it be better to just run my jets off a power head? or just a second pump from my sump?

 

[Egon]

ok that is what i was thinking do you think getting rid of the barb fittings will help?

also could i just not use the top outlet just leave the ball valve open enough to work as a siphon break. my overflow goes through a wet dry tower and then into a sump so i think my water will get plenty of agitation.

last would it be better to just run my jets off a power head? or just a second pump from my sump?

1) Barb fittings are okay if they are the right size. I always stick with my pump return fitting as a guide for the rest of the plumbing. Yours is 1" so you should have 1" barbs going to 1" hose and using 1" pvc everywhere. If your barb fitting are 1/2" and your hose is 1/2" then you have a problem. Make sense?

2) Yes you will be fine with the ball valve open for a siphon break.

3) I think you have pipe routing or constriction issues in your system from the barb question? Your pump should be strong enough to run both the upper system and the under gravel jets.

• Check the intake of the pump and make sure it's clear of debris.
• You should have 1" plumbing from the pump all the way to the bottom of the fish tank. It's okay to have the ends pinched shut on the under gravel jets if you have more than one.
• minimize bends in the plumbing for example: two 45 bends are better than one 90. Y fittings are better than T fittings.
• Ace or a similar hardware store has all these barb type fittings in 1" sizes. Just run that flexible vinyl black hose from your pump to the top of your tank, then put a Y barb fitting in with a valve on the upper jet. The lower jets don't need a valve. The other side of the Y can go directly to the PVC Under gravel Jet system.

 

[rotccapt]

here is my setup i am using 1 inch barb fittings and 1 inch hose i was just asking about the barb fittings because the inside of the barb constricts to 3/4 inch. i could step up to 1.25" barbs that would open up the tubing diameter

the ugj arms are 3/4 inch pvc the center tube is 1 inch pvc

so if i under stand you right i should cut out my existing setup and replace it with all flexible tubing and a Y instead of my T

 

[Egon]

Na, the PVC looks good! Definitely there's something going on with the barb fitting. It looks too small. I think the easiest thing to do is cut that barb fitting off and run pvc from your pump to where that barb fitting is.

Flexible PVC is great here's a few pics of my set up. You can do the same thing from your threaded quiet one pump return. Get a 1" threaded piece to a PVC union, I'm using a threaded union to a threaded barb then a 1" braided line to.......my return (the cheapest easiest way IMO) OR after the PCV union you can go to a flexible PVC pipe to the barb area of your set up.

Tip:Working with flexible PVC don't use primer, it gets to soft and takes forever to set up.

 

[Egon]

Damn your right the 1" barbs go down to 3/4". I took a couple pictures of a 1" barb and a 1" threaded PVC piece and there's a difference. I also have a 1/2" Y barb fitting just to show you.

I don't know what to tell you? I think I would go with just PVC or flex PVC and stay away from the barb fittings? The flex PVC is really nice to work with and the long sweeping bends really help the head loss issue. Good luck man, I admire you plywood build guys! Keep us posted on how that build works out!

 

[rotccapt]

i think what i am going to do is look at the hardware store and see if the next size up in barb fittings is at 1 inch if so i will go that route

 

[rotccapt]

well i think i got my problem fixed i went back to the store and picked up some 1 1/4 inch barbs and tubing the inside diameter of the barb is exactly 1 inch so there is not any restriction there but i wont be able to see till the weekend my acrylic arrived so the tank is sitting on its front with the acrylic and silicone drying