Long time hard pipe plumber will never do it again.

[LobsterOfJustice]

I can't imagine any of the pumps we use being strong enough to pop hose off a properly sized barb fitting. I use hose on a PVC hook for water changes and its' a PIA to remove the hose from time to time from the barb and there's no clamp or zip tie on it at all.

I know it seems like that when you’re using every ounce of your strength to shove the hose into the barb, but trust me, they can fly off. Over time the hose can lose elasticity and become used to the new stretched out size. One, two, maybe five or more years later it can come flying off. Happened to me, return pump turned into a geyser in the sump. Please please please use metal (plastic if you have to, die to submerged) hose clamps on all barb fittings.

 

[Fritzhamer]

Didn’t think about that but that makes a lot of sense. I periodically trim the ends off when they seem like they’ve become hardened. Until now I wasn’t using any hose except for water changes now and again. I’ve got some stainless steel jubilee clamps I’ll be adding on tonight. Thanks.

 

[Sleepydoc]

If the only schedule 80 you had was the fittings they probably had little to no effect on your flow.

I've never used the ultra flex PVC but have seen several other people use it. It looks nice and much better than regular spa-flex. The regular spa flex is still flexible, but still pretty stiff. I've had some luck putting it in hot water and then letting it cool in the desired position. I've never had it leak though, and they use it all the time for hot tubs, etc without an issue. The manufacturer recommendations I've seen are not to prime flexible PVC. The purpose of PVC primer is to soften the plastic and let the glue penetrate further. Flex PVC is already soft, so primer would soften it too much.

As for vinyl tubing, Lobster's story is exactly what I was referring to. It's not that it 'blows' off immediately, but it gets hard over time and will gradually work its way off. The braided tubing can definitely be rather stiff, too, even when new - I've had to soak it in hot water to get it to do what I wanted. I had some tubing I used with a Maxijet 12 for water changes, etc. I ended up replacing it with silicone tubing from BRS which is a thousand times.

 

[rcmike]

I just did a test on my Mag 18 or 24, I can't remember which it is, on my mixing station. Output fully open with probably 4 or 5 feet of 1"PVC and a few elbows was 189 W. Output fully closed was 98 W. Fully open was twice the wattage as fully closed!

 

[rockskimmerflow]

I just did a test on my Mag 18 or 24, I can't remember which it is, on my mixing station. Output fully open with probably 4 or 5 feet of 1"PVC and a few elbows was 189 W. Output fully closed was 98 W. Fully open was twice the wattage as fully closed!

Yup that's how it works exactly. Always nice to see it for yourself firsthand to crystallize the principle in one's mind. My iwaki 100rlt on my 300gal salt mix drum uses 375 watts roughly at wide open and something like 240 if the valve is shut off.

 

[KStatefan]

What really matters, though is gallons per hour per watt. I'd be interested to see a comparison of the efficiency of various pumps at various head pressures.

I wish aquarium pump manufacturers would publish pump power curves in addition to flow curves like industrial pumps have. Most of the centrifugal pump power curves I have looked at show the pumps the most efficiant around 75% of max flow.