200 freakin' gph return pump problem

[malira]

Earlier I had a thread claiming my QuietOne 4000 wasn't putting out the 400 to 500 gph that it was supposed to with 4ft head pressure.
So I bought a Jebao DCS 7000 that is suppposed to put out around 900 gph at 4ft head pressure. When I installed it, I notice it had more power but still not enough. I have it turned all the way up. I checked it last night and I calculated it was putting our only 200 gph. 200 freakin' gph.I have a 90 gallon DT with 35 gallon in the sump.
I got a 1/2 gallon pitcher put it under the return pipe and I timed it. It took 9 seconds to fill up. So its 18 seconds for a gallon = 3.33 gallons per minute = 200 gph. Now I may be off by a few gallons but not much.

I should be getting 900 gph.
My return water is in a 5/8 flexible hose which only has one elbow before it goes into the return pipe.
The PVC is the drain pipe. This is a Jebao DCS 7000 1849 gph pump with controller. It should be putting out 900 gph at 4ft.

I have a new hose that is 3/4 flex hose that I want to change out but I need answers and advice.
Does the chocking down of the pump outlet change the gph output?
Do I need to go to a bigger hose to get the 900 gph?
Do you see any glaring problems with the set up?
If I need to change what is the easiest way to cut the bottom of the stand to access the return bulkhead?


Thanks in advance.

Mario

 

[malira]

This is what it comes with. I am using the top opening. It's 3/4 inches. The hose I have is 3/4 inches.

 

[Reefpro]

Yes choking it down will for sure slow it down. More pressure but less volume if that makes sense

 

[malira]

Yes choking it down will for sure slow it down. More pressure but less volume if that makes sense

Yes it does. But my QuietOne 4000 had the same problem. It was worse.

 

[malira]

Yes it does. But my QuietOne 4000 had the same problem and it didn't neck down ot the outlet. It was worse.

Would getting rid of the elbow help relieve any of the head pressure?

 

[redfishbluefish]

Your biggest killer of head loss is the diameter of the tubing/fittings. I'm looking at the elbow and guessing the ID is about 1/2 inch. Go up to 1 inch on tubing and you will see a considerable increase in flow. If you can swing it, even larger diameter pipe would help even more.

 

[hybridazn]

The gph ratings with headloss are calculated with a straight pipe, so any horizontal runs, elbows, fittings, valves and so on will slow it down dramatically.

I know it's a link to the other site, but the headloss calculator should tell you if your pump is underperforming

http://www.reefcentral.com/index.php/head-loss-calculator

 

[Rjramos]

The specs on any pump capacity output vs. head pressure( height) are on same diameter pipe as pump outlet straight up vertically without any reducing nozzle on the end.

 

[malira]

Your biggest killer of head loss is the diameter of the tubing/fittings. I'm looking at the elbow and guessing the ID is about 1/2 inch. Go up to 1 inch on tubing and you will see a considerable increase in flow. If you can swing it, even larger diameter pipe would help even more.

I wouldn't mind doing that but I would need to cut an access hole to change the bulkhead.
Any suggestions? My hand hand jigsaw might not be the best option.

 

[ckozma]

Would getting rid of the elbow help relieve any of the head pressure?

Yes, this is greatly reducing your GPH. Just stick the hose straight onto the bulkhead.

 

[malira]

The gph ratings with headloss are calculated with a straight pipe, so any horizontal runs, elbows, fittings, valves and so on will slow it down dramatically.

I know it's a link to the other site, but the headloss calculator should tell you if your pump is underperforming

http://www.reefcentral.com/index.php/head-loss-calculator

When I input my systems parameters I should be getting 800+ gph. So there is another problem. I need to replace all the return pump pipes.

 

[Rjramos]

I wouldn't mind doing that but I would need to cut an access hole to change the bulkhead.
Any suggestions? My hand hand jigsaw might not be the best option.

What size is the bulkhead coming back in 3/4"? If it is I would leave it, pipe 1" and reduce to 3/4" right under the bulkhead. From there you have to go 3/4" the rest of the way up. Place a 3/4" tee up top and split to 2-1/2" loctite nozzles. Better than this you won't get! Unless you go with a pressure rated pump that overcomes head better. I would not get into making that bulkhead hole bigger on glass! There is nothing in the middle to guide the pilot bit, and the risk of cracking your tank is great! Hope this helps.[emoji4]

 

[malira]

What size is the bulkhead coming back in 3/4"? If it is I would leave it, pipe 1" and reduce to 3/4" right under the bulkhead. From there you have to go 3/4" the rest of the way up. Place a 3/4" tee up top and split to 2-1/2" loctite nozzles. Better than this you won't get! Unless you go with a pressure rated pump that overcomes head better. I would not get into making that bulkhead hole bigger on glass! There is nothing in the middle to guide the pilot bit, and the risk of cracking your tank is great! Hope this helps.[emoji4]

Thanks. Yes the pipe is 1 inch, the fitting reduces to a 3/4 barb. The water flows into the tank in one pipe that y's to 2 outlet hoses. I need to look up the loctite nozzles.

I wasn't looking to drilling the tank. Just maybe widening the access hole in the stand.

 

[hybridazn]

Also when you timed the water coming out did you wait for the pump to hit full speed? Dc pumps all have soft starts and take about 10-15 seconds to reach full speed

 

[malira]

Also when you timed the water coming out did you wait for the pump to hit full speed? Dc pumps all have soft starts and take about 10-15 seconds to reach full speed

Yes. I never stopped the pump. I disconnected the pipe and put the 1/2 gallon pitcher under it.

Crappy pic but like this.

 

[malira]

We have success.
I changed out the 5/8" hose with a 3/4". I also took out the elbow at near the bulkhead.

I started at 200 gph.
At the pumps lowest speed #1 - I was at 240 gph.
There are 10 speed. At #10 we have just over 600 gph.
I don't need any more than that.
So 1/8 inch (really more like 3/16) more in diameter and removing a 90 degree turn and I tripled the gph.

I could literally see debris/detritus being moved and suspended in the water column. It wasn't there before. The sandbed is not moving but detritus is being lifted. It is remarkable the difference.
Now hopefully the micro/nano bubbling will help speed the dinos and cyano away.

This is what was removed and what was put in.

 

[BoneXriffic]

Well seems you got it. In plumbing systems reducing pipe size decreases volume and increases velocity. Allows for higher pressure but lower gph.

 

[malira]

Well seems you got it. In plumbing systems reducing pipe size decreases volume and increases velocity. Allows for higher pressure but lower gph.

Thanks.
It seems that I am tapped out getting just about all I can out of a 3/4 inch hose. I could approach 800 gph if I went to 1" which I could do but it's unnecessary.

The tank tank is 90g so the turn over rate is just over 6 times which is perfect.

 

[BoneXriffic]

Good contact time....im moving about 800gph in a 29 with a 12gal sump lol....20x which im sure isnt great...but parameters have been almost always in check for a year

 

[Waterjockey]

Double the pipe/hose diameter = 4x the flow.

Cheers