closed loop/ampmaster intake holes?

organicreefer · 08-22-2001, 10:13 PM

you guys think i could use the 2 3/4 inch "return" bulkheads on my oceanic as an intake on an ampmaster 3600?i would elbow the returns about half way up.the pipe would be plumbed through the overflow boxes,with bulkheads or whatever and have screens on them.underneath the tank i wouldplumb both to 1 1/2 inch pipe to the ampmaster.would it work?3/4 +3/4 =1 1/2 ,but i guess the amount of flow would be constricted by the extra plumbing.any help/advice/suggestions appreciated

**golfish** · 08-23-2001, 04:22 AM

in this case 3/4 + 3/4 doesn't equal 1.5...it will work, just not very good. I would make a U-tube out of 1.5" PVC.

Mark

dsb1829 · 08-23-2001, 12:21 PM

As Mark mentioned, not equal. Flow is dependent upon the cross sectional area of the pipe. In this case 2x3/4 = 1/2 the area of a 1.5". That is also not considering the restriction of flow on the pump. If the pump cannot get enough flow it will cavitate and cause damage to the impeller. You could throttle it back, but you would need to restrict the pump to less than half of its full flow.

If you do decide to use 1.5" elbow to get it over the wall to the pump I would recommend using a couple of 1.5" lines over the wall T'd into a 2" line. By doing this you will effectively reduce the effect of head on the pump and also have slower exit from the tank. The slow exit is important if you have fish that aren't powerful swimmers that could get caught by the outflow.

**Ninong** · 08-23-2001, 01:05 PM

As has already been pointed out, 2 x 3/4" returns = 0.88357 square inches total area. Dolphin says that you can use that pump with either a 1" or a 1.5" inlet/outlet. With a 1" inlet the rating is 1500gph. Since a 1" inlet has an area of 0.78540 square inches and is rated by Dolphin as 1500gph, we can assume that 2 x 3/4" inlets would yield a maximum of approximately 1687gph. For comparison, the recommended 1.5" inlet has an area of 1.7671 square inches.

Ninong

tendar · 08-23-2001, 02:12 PM

The other problem will be that oceanic overflows can only handle 800 gph per overflow. So with 2 over flows you will only be able to drain 1600 gph with the over flows which isnt near enough for the dolphin so the U tube idea would be the better idea.

JG · 08-23-2001, 02:42 PM

the Oceanic overflows can handle a lot more the 800gph. I'm running a Mag 12 with no problems at all in my 58 Oceanic. I could probably run Mag 18 if I wanted too.

**golfish** · 08-23-2001, 06:08 PM

I don't think he plans to use the overflows in the closed loop (it won't be a closed loop then) He plans to use the 3/4" return lines.

Anther thought would be to have the tank drilled for a 1.5" bulkhead. Since the tank is empty now would be the time to do it.

organicreefer · 08-23-2001, 06:21 PM

golfish,there is no place around here ,that i have found, that wants to touch it they dont make me feel at all comfortable about it

how would the u tube work?would it break syphon?i guess not as long as the output is underwater huh?i thought i saw a picture of someone using a u tube on a closed loop but i cant remember who.

**golfish** · 08-23-2001, 07:40 PM

Check out this thread, there is a picture of a U-tube used on a closed loop. I used gray pipe rather then white

Closed loops and plumbing them! pics plez

organicreefer · 08-23-2001, 08:50 PM

thats the one.so it wont break syphon when you shut down the pump?do you have to "prime it " like a hang on overflow to get it going?what aboutwhen the water level goes down ,like in a water change ,you would have to re prime it.sorry if my questions arent good ones.it looks TOO simple

**golfish** · 08-23-2001, 09:35 PM

There is no siphon to break. It looks simple becaue it is. dsb1829 has a good point about using 2 U-tubes. The water is sucked out pretty fast. Make sure you have a screen on the intake.

organicreefer · 08-23-2001, 09:48 PM

soyou just hook up the pump and plug it in and it will suck the water on its own.i dont own the ampmaster yet,but my iwakis need to be primed i guess once the water is there that is the lowest point and it will always be there huh.ok.duh.

organicreefer · 08-23-2001, 09:51 PM

yes two tubes does sound like a good idea.

**golfish** · 08-23-2001, 10:32 PM

This is one of those things that's so simple its hard to believe we can use it

I use only one 1.5" u0yube and have no problem feeding the pump. I have yet to stick a fish to the strainer.

Mark

Ironreef · 08-23-2001, 11:52 PM

I belive you need to prime it the first time you hook it up. I have a closed loop on my spraybar on the bottom of my tank. But my in take is only5-6 into the tank. I have no bubbles. So it doesn't need to be as long as the pic ime. I tried both ways but like to look at less pvc.

**golfish** · 08-24-2001, 09:38 AM

I can't speak for any other pump then the AM3000...You shouldn't need to prime it, I didn't. If the intake doesn't go down far enough into the tank you will get a vortex (I'm not sure if that is the correct word I'm looking for) It will swirl water down from the top and may suck air.

Mark

Ironreef · 08-24-2001, 10:14 PM

The amp master will pull water down with air then start on its own? Must because of the power? Enough to get water down? I know most all external pumps need water in the line. Probally why the sucking of air also. I guess my puny Iwaki30 can handle a short intake.But it works good for my spraybar on the bottom. One day I'll probally get a dolphin. I like those pumps.

organicreefer · 08-25-2001, 12:18 PM

ironreef ,by my calculations by replacing my iwaki 100rlt with an ampamaster 3600,the ampmaster will pay for itself in 11 months,on energy savings

Ironreef · 08-25-2001, 08:22 PM

I would take the dolphin(amp master 3000) over any Iwaki except if I needed a high pressure situation. But dolpin make pressure aqua pumps also. I seen many in action they are good pumps.

08-22-2001, 10:13 PM	#1
organicreefer Governor Join Date: May 2001 Location: Northern CA Posts: 2,171	closed loop/ampmaster intake holes? you guys think i could use the 2 3/4 inch "return" bulkheads on my oceanic as an intake on an ampmaster 3600?i would elbow the returns about half way up.the pipe would be plumbed through the overflow boxes,with bulkheads or whatever and have screens on them.underneath the tank i wouldplumb both to 1 1/2 inch pipe to the ampmaster.would it work?3/4 +3/4 =1 1/2 ,but i guess the amount of flow would be constricted by the extra plumbing.any help/advice/suggestions appreciated

08-23-2001, 01:05 PM	#4
Ninong Moderator Join Date: Jun 2000 Location: Louisiana Posts: 19,500	As has already been pointed out, 2 x 3/4" returns = 0.88357 square inches total area. Dolphin says that you can use that pump with either a 1" or a 1.5" inlet/outlet. With a 1" inlet the rating is 1500gph. Since a 1" inlet has an area of 0.78540 square inches and is rated by Dolphin as 1500gph, we can assume that 2 x 3/4" inlets would yield a maximum of approximately 1687gph. For comparison, the recommended 1.5" inlet has an area of 1.7671 square inches. Ninong __________________ Ninong

08-23-2001, 09:48 PM	#12
organicreefer Governor Join Date: May 2001 Location: Northern CA Posts: 2,171	soyou just hook up the pump and plug it in and it will suck the water on its own.i dont own the ampmaster yet,but my iwakis need to be primed i guess once the water is there that is the lowest point and it will always be there huh.ok.duh. Last edited by organicreefer; 08-23-2001 at 09:58 PM.

08-24-2001, 10:14 PM	#17
Ironreef Governor Join Date: Aug 2000 Location: Pacific WA Posts: 1,220	The amp master will pull water down with air then start on its own? Must because of the power? Enough to get water down? I know most all external pumps need water in the line. Probally why the sucking of air also. I guess my puny Iwaki30 can handle a short intake.But it works good for my spraybar on the bottom. One day I'll probally get a dolphin. I like those pumps. Last edited by Ironreef; 08-24-2001 at 10:19 PM.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

08-23-2001, 04:22 AM	#2
golfish Moderator Join Date: Jun 2000 Location: Alta Loma,Ca Posts: 2,925	in this case 3/4 + 3/4 doesn't equal 1.5...it will work, just not very good. I would make a U-tube out of 1.5" PVC. Mark

08-23-2001, 12:21 PM	#3
dsb1829 Council Join Date: Jul 2000 Location: Santa Cruz,CA Posts: 438	As Mark mentioned, not equal. Flow is dependent upon the cross sectional area of the pipe. In this case 2x3/4 = 1/2 the area of a 1.5". That is also not considering the restriction of flow on the pump. If the pump cannot get enough flow it will cavitate and cause damage to the impeller. You could throttle it back, but you would need to restrict the pump to less than half of its full flow. If you do decide to use 1.5" elbow to get it over the wall to the pump I would recommend using a couple of 1.5" lines over the wall T'd into a 2" line. By doing this you will effectively reduce the effect of head on the pump and also have slower exit from the tank. The slow exit is important if you have fish that aren't powerful swimmers that could get caught by the outflow.

08-23-2001, 02:12 PM	#5
tendar Governor Join Date: May 2000 Location: tempe,AZ Posts: 1,114	The other problem will be that oceanic overflows can only handle 800 gph per overflow. So with 2 over flows you will only be able to drain 1600 gph with the over flows which isnt near enough for the dolphin so the U tube idea would be the better idea.

08-23-2001, 02:42 PM	#6
JG Mayor Join Date: Jul 2000 Posts: 630	the Oceanic overflows can handle a lot more the 800gph. I'm running a Mag 12 with no problems at all in my 58 Oceanic. I could probably run Mag 18 if I wanted too.

08-23-2001, 06:08 PM	#7
golfish Moderator Join Date: Jun 2000 Location: Alta Loma,Ca Posts: 2,925	I don't think he plans to use the overflows in the closed loop (it won't be a closed loop then) He plans to use the 3/4" return lines. Anther thought would be to have the tank drilled for a 1.5" bulkhead. Since the tank is empty now would be the time to do it.

08-23-2001, 06:21 PM	#8
organicreefer Governor Join Date: May 2001 Location: Northern CA Posts: 2,171	golfish,there is no place around here ,that i have found, that wants to touch it they dont make me feel at all comfortable about it how would the u tube work?would it break syphon?i guess not as long as the output is underwater huh?i thought i saw a picture of someone using a u tube on a closed loop but i cant remember who.

08-23-2001, 07:40 PM	#9
golfish Moderator Join Date: Jun 2000 Location: Alta Loma,Ca Posts: 2,925	Check out this thread, there is a picture of a U-tube used on a closed loop. I used gray pipe rather then white Closed loops and plumbing them! pics plez

08-23-2001, 08:50 PM	#10
organicreefer Governor Join Date: May 2001 Location: Northern CA Posts: 2,171	thats the one.so it wont break syphon when you shut down the pump?do you have to "prime it " like a hang on overflow to get it going?what aboutwhen the water level goes down ,like in a water change ,you would have to re prime it.sorry if my questions arent good ones.it looks TOO simple

08-23-2001, 09:35 PM	#11
golfish Moderator Join Date: Jun 2000 Location: Alta Loma,Ca Posts: 2,925	There is no siphon to break. It looks simple becaue it is. dsb1829 has a good point about using 2 U-tubes. The water is sucked out pretty fast. Make sure you have a screen on the intake.

08-23-2001, 09:51 PM	#13
organicreefer Governor Join Date: May 2001 Location: Northern CA Posts: 2,171	yes two tubes does sound like a good idea.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

08-23-2001, 10:32 PM	#14
golfish Moderator Join Date: Jun 2000 Location: Alta Loma,Ca Posts: 2,925	This is one of those things that's so simple its hard to believe we can use it I use only one 1.5" u0yube and have no problem feeding the pump. I have yet to stick a fish to the strainer. Mark

08-23-2001, 11:52 PM	#15
Ironreef Governor Join Date: Aug 2000 Location: Pacific WA Posts: 1,220	I belive you need to prime it the first time you hook it up. I have a closed loop on my spraybar on the bottom of my tank. But my in take is only5-6 into the tank. I have no bubbles. So it doesn't need to be as long as the pic ime. I tried both ways but like to look at less pvc.

08-24-2001, 09:38 AM	#16
golfish Moderator Join Date: Jun 2000 Location: Alta Loma,Ca Posts: 2,925	I can't speak for any other pump then the AM3000...You shouldn't need to prime it, I didn't. If the intake doesn't go down far enough into the tank you will get a vortex (I'm not sure if that is the correct word I'm looking for) It will swirl water down from the top and may suck air. Mark

08-25-2001, 12:18 PM	#18
organicreefer Governor Join Date: May 2001 Location: Northern CA Posts: 2,171	ironreef ,by my calculations by replacing my iwaki 100rlt with an ampamaster 3600,the ampmaster will pay for itself in 11 months,on energy savings

08-25-2001, 08:22 PM	#19
Ironreef Governor Join Date: Aug 2000 Location: Pacific WA Posts: 1,220	I would take the dolphin(amp master 3000) over any Iwaki except if I needed a high pressure situation. But dolpin make pressure aqua pumps also. I seen many in action they are good pumps.