Do barbed fittings slow down flow rate? Size of return line?
 

So I'm building my first salt setup and my 150 g will be plumbed to a 55 gallon sump in basement. I drilled my 150 and installed a 3 drain bean animal overflow system that I purchased. My return is drilled for 3/4". My overflow box has 1" bulkheads and will drain through sc40 1" standpipes. I have no choice but to use 1" braided vynil tubing for the rest of the run to basement. I thought my return size should be smaller then my drainage lines so that the overflow is always ahead of the return. Now if I use the 1" pvc standpipes fitted with a barbed adapter to fit the vynil hose will I lose a lot of the drain flow due to the smaller inner diameter of the barbed fitting? Does it really matter?

Also would you just use 3/4" hose for return? Someone mentioned adapter to make the return pipe 1" even though the bulkhead is only 3/4" in order to decrease head pressure on pump. The local plumbing shop said to just use 3/4". What do you think?

Yes, barbed fittings definitely add significantly to head pressure and therefore reduce flow. I was plumbing a Fluval SP4 and tried it with a section of vinyl tubing and then a section of flex PVC. The tubing had about a 15% drop in flow IIRC. Best way to see this is to look at the size of the hole on a ¾" barbed connector. It's closer to ½"

Can you use spa flex or ultra flex PVC? They will give you the flexibility of vinyl tubing without the drawbacks.

Regarding the return plumbing, plumbing resistance is additive, so even though your bulkhead is 3/5", there is likely some benefit to upsizing the pipe. I'd play around with some headless calculators to try and get an ide how big of a difference it will make.

The barbed fittings would be on the 3 drains. Could I just use a street fitting with a clamp?

I already bought the braided vynil. What do you mean by flex pvc or the spa flex? Do you have a link?

http://www.marinedepot.com/Ultra_Fle...FTTUFP-vi.html
You use regular pvc fittings. Most hardware stores sell the white flexible pvc
http://www.homedepot.com/p/Sioux-Chi...0504/202257769

If you already have the all the hoses and fittings use it. You should be fine. A 3/4" drain at full siphon will have enough capacity to keep up with your return. Not to mention you have 3 drains..... Yes it reduces flow but for your drain, not a concern. You return line is a different story, you do want to reduce the number and type of fittings you use.

OK thanks for the info. I had all the hard pipe but couldn't make the turns I needed to. this will save lots of hassle. Will I be ok to use the 3/4" vynil for the return line or should I use adapters to be able to use 1". I bought a bulkhead that is threaded on both sides for the return as per a recommendation and now I'm finding the adapters to get to 1" make it stick out real far and make it less stable.

I'm finding this venture very stressful since I want to get it right the first time and not mess around later. Been doing fresh for over 20 years and salt is a hole new world to me. A whole lot to learn at once if I want to plan ahead.

Vinyl is fine for the return. What kind of pump are you using and have you calculates the head pressure yet?

So your saying just keep it all 3/4 " for return? I haven't bought it yet. I've been looking at controllable DC pumps. I've figured I would purchase it after I know how many fittings and what my sump design is going to be. Ill be pushing it up about 8 ft. My overflow max rate is 1500 gph so I thought I would get something bigger and controllable in case I want to run some reactors or a refugium and still be able to slow it down if needed, I have a 55g tank I will be using to build sump and will be having glass cut locally to make dividers, bubble traps etc..

Any recommendations or things I should consider before buying pump?

3/4" is fine. What bulkheads do you have? Also start looking at what pump you want because it could have either a 1" or 3/4" fittings

If you bulkhead is 1" use 1" vinyl.

The straighter you make the return, larger ID of tubing, and fewer fittings will give you the most flow. I use 1" on my 3/4" iwaki.

I was told to order threaded for the return so I buy http://www.petsandponds.com/en/aquar...p17694004.html

I can always order another.

The overflow kit is http://www.elite-aquatics.net/index....&product_id=44

I doubt there would be any appreciable reduction in flow due to barbed fittings vs. any other type of fitting because they are pretty smooth on the inside. Hose/pipe diameter and the number of bends does have a greater effect on flow.

+1

I'm trying to squeeze a little more flow from my return pump and am thinking of replacing the dual barb/vinyl tube with ultra flex.

How does that change anything? What's different about that hose compared to vynil braided? The fittings?

Yes, it's the fittings not the hose. Take a look inside a 1" barb fitting versus a standard 1" PVC male adapter - the former is substantially narrower than the latter. Now, in many applications it may not matter. In my case, my return pump is on the small side for my tank so I am trying to find ways to squeeze a little more flow out of it. With the ultra flex, you can solvent weld it into a standard sch 40 pvc fitting; no way to do that with vinyl hose; so either you oversize the latter so that you use, for example, 1 1/2" barb fittings, or you just live with the restrictions.

So this is my own conclusion, I know I'm a newb but... I found a 1" sc40 union I didn't return. I measured the inner diameter of the union and it's 7/8 of an inch. I then took the barb that fits the 1" vynil tubing and the inner diameter is 7/8. Evryone said unions unions unions. To make easy to disconnect I would have had 4 unions on each line for convenience and diconnects. So I would have had 4 unions dropping to 7/8 inner diameter 4 times. With the vynil I will only have 1 barb dropping to 7/8 once and 1 union at the standpipes on overflow box.. So in reality I have less restrictions using vynil as far as flow rates go.

I'm glad i dint return the union so now I have the piece of mind knowing it's the same inner diamter as the vynil barb fitting.

Ty for all your help people I get overwhelmed sometimes and appreciate the help

Do they make colored spa flex? Can anyone send me a link to a cheap place to pick some up?

I found it today at local pool and hot tub store. It was all black clear or blue

This doesn't answer your question, but don't use krylon fusion to spray paint flex PVC - I've read several stories of people trying and it ends up ruining the surface.

Thanks