I hear more flow more flow...

doox00 · 03/27/2006, 09:53 PM

I have a 90g, mag 9.5 return pump from sump, a mj 900 in the tank and some other powerhead that is similar in gph as the mj900, this enough flow? the mag 9.5 only has about 4.5" of head so its pushing 750ish gph into the tank via the 2 return spouts aimed in each direction.

Is there a thing as to much flow? Don't the fish need a calm place to rest sometimes? seems with all this flow, some people saying to use 4 ph's in a 90g that the fish would be on permanent marathons.

sjm817 · 03/27/2006, 10:00 PM

What diameter plumbing are you using on the Mag9?

PatMayo · 03/27/2006, 10:12 PM

How did you end up with only 4.5 inches of head.

I have a 90 with 4 powerheads. My sig has what is in there. The fish manage to find calm places. With the rock work in the tank it makes calmer areas of water for the fish to take cover. They don't seem to have any problems.

Keep this in mind, I have zero algae problems in my tank I credit this in part to the flow and starting off with fully cured rock.

Regards,

Pat

doox00 · 03/27/2006, 10:16 PM

meant 4.5' of head, I am using 3/4", same size coming off the mag 9.5.

sjm817 · 03/27/2006, 10:19 PM

Most people do that. You have a huge flow restriction. The Mag needs big plumbing to flow well. The instructions say to use 1.5". You need a bare minimum of 1" for decent flow, 1.25" - 1.5" for good flow.

doox00 · 03/27/2006, 10:34 PM

I do not see how it could make much difference when coming out of the mag is 3/4 and going back into the tank is 3/4, I do not see how having larger pipe inbetween makes it less back pressure and more flow. My return splits and shoots out of two flex nozzles into the tank, and there is a whole lot of force coming out of both.

sjm817 · 03/27/2006, 10:43 PM

It doesn't seem logical at first, but it has been proven many times over. It has to do with frictional loss in the pipe. I made the same mistake as have may others. You will be shocked at the difference if you make the change. 3/4" is a huge reduction in flow.

Here are in Mag installation instructions

Look underneath the chart.

ChunksInClemson · 03/27/2006, 11:20 PM

Just to state the obvious, when you go from bigger to smaller tubing, it creates more pressure. I have worked with a little bit of irrigation and this is an understood rule. I also have a 90g with a Mag 9.5 and I am going from 3/4" to 5/8". It was what the guy who I bought the tank from had it plumbed with and he has 12 years of experience so I have to go with my boy on that one. I only have one outlet and it seems to be more than enough. I am also running a MJ-1200.

Doox, where do you have the returns directed? It sounds to me like you have enough flow.

sjm817 · 03/27/2006, 11:23 PM

ChunksInClemson, you are looking to cut the flow back more than the 3/4" does? Why not use a smaller pump or a ball valve?

BTW, if you want good flow without the need for large plumbing, you need to use a pump that handles head pressure much better than a Mag which is a flow pump. In submersibles, the Eheim pumps are great at this. Unlike the Mags, plumbing dia has little effect.

ChunksInClemson · 03/27/2006, 11:35 PM

I didnt start the post and everything is well with my tank so I'm not changing anything. I soft piped everything BTW. Im not using a smaller pump b/c I already bought the Mag 9.5 and I got it for a deal. I'm just doing what my friend did. He's a pretty smart guy, like I said, been in it for 12 years.

sjm817 · 03/27/2006, 11:47 PM

If it works for you, that's cool.

I just never understand why people buy big pumps, then choke the flow back. I guess I'm a stickler for efficiency.

03/27/2006, 09:53 PM	#1
doox00 Premium Member Join Date: Feb 2006 Location: West Michigan Posts: 928	I hear more flow more flow... I have a 90g, mag 9.5 return pump from sump, a mj 900 in the tank and some other powerhead that is similar in gph as the mj900, this enough flow? the mag 9.5 only has about 4.5" of head so its pushing 750ish gph into the tank via the 2 return spouts aimed in each direction. Is there a thing as to much flow? Don't the fish need a calm place to rest sometimes? seems with all this flow, some people saying to use 4 ph's in a 90g that the fish would be on permanent marathons.

03/27/2006, 10:00 PM	#2
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	What diameter plumbing are you using on the Mag9? __________________ - Scott

03/27/2006, 10:12 PM	#3
PatMayo Registered Member Join Date: Sep 2005 Location: Seattle Posts: 2,843	How did you end up with only 4.5 inches of head. I have a 90 with 4 powerheads. My sig has what is in there. The fish manage to find calm places. With the rock work in the tank it makes calmer areas of water for the fish to take cover. They don't seem to have any problems. Keep this in mind, I have zero algae problems in my tank I credit this in part to the flow and starting off with fully cured rock. Regards, Pat __________________ 90 AGA Megaflow (Setup 1-24-06) 120 Lbs. Liverock EuroReef RS 100 Skimmer 2 X 150 MH 2 X 96 watt PC Actinic 2 Clarki Clowns (31 months old) 1 Niger Trigger (Owned 6 months) 2 Tunze 6055 PH Current Tank Info: 90 AGA Megaflow To Be Mixed Reef

03/27/2006, 10:19 PM	#5
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	Most people do that. You have a huge flow restriction. The Mag needs big plumbing to flow well. The instructions say to use 1.5". You need a bare minimum of 1" for decent flow, 1.25" - 1.5" for good flow. __________________ - Scott

03/27/2006, 10:43 PM	#7
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	It doesn't seem logical at first, but it has been proven many times over. It has to do with frictional loss in the pipe. I made the same mistake as have may others. You will be shocked at the difference if you make the change. 3/4" is a huge reduction in flow. Here are in Mag installation instructions Look underneath the chart. __________________ - Scott

03/27/2006, 10:16 PM	#4
doox00 Premium Member Join Date: Feb 2006 Location: West Michigan Posts: 928	meant 4.5' of head, I am using 3/4", same size coming off the mag 9.5.

03/27/2006, 10:34 PM	#6
doox00 Premium Member Join Date: Feb 2006 Location: West Michigan Posts: 928	I do not see how it could make much difference when coming out of the mag is 3/4 and going back into the tank is 3/4, I do not see how having larger pipe inbetween makes it less back pressure and more flow. My return splits and shoots out of two flex nozzles into the tank, and there is a whole lot of force coming out of both.

03/27/2006, 11:20 PM	#8
ChunksInClemson Registered Member Join Date: Feb 2006 Location: Anderson, SC Posts: 824	Just to state the obvious, when you go from bigger to smaller tubing, it creates more pressure. I have worked with a little bit of irrigation and this is an understood rule. I also have a 90g with a Mag 9.5 and I am going from 3/4" to 5/8". It was what the guy who I bought the tank from had it plumbed with and he has 12 years of experience so I have to go with my boy on that one. I only have one outlet and it seems to be more than enough. I am also running a MJ-1200. Doox, where do you have the returns directed? It sounds to me like you have enough flow. __________________ Me to my brother-"Dude, you don't need to spend 75 dollars on a shirt! My brother to me-"Man, you just spent 100 dollars on some rocks" Me and him- "Laughs" Current Tank Info: 29g, a pair of true percs so far. Tank is newer!

03/27/2006, 11:23 PM	#9
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	ChunksInClemson, you are looking to cut the flow back more than the 3/4" does? Why not use a smaller pump or a ball valve? BTW, if you want good flow without the need for large plumbing, you need to use a pump that handles head pressure much better than a Mag which is a flow pump. In submersibles, the Eheim pumps are great at this. Unlike the Mags, plumbing dia has little effect. __________________ - Scott

03/27/2006, 11:35 PM	#10
ChunksInClemson Registered Member Join Date: Feb 2006 Location: Anderson, SC Posts: 824	I didnt start the post and everything is well with my tank so I'm not changing anything. I soft piped everything BTW. Im not using a smaller pump b/c I already bought the Mag 9.5 and I got it for a deal. I'm just doing what my friend did. He's a pretty smart guy, like I said, been in it for 12 years. __________________ Me to my brother-"Dude, you don't need to spend 75 dollars on a shirt! My brother to me-"Man, you just spent 100 dollars on some rocks" Me and him- "Laughs" Current Tank Info: 29g, a pair of true percs so far. Tank is newer!

03/27/2006, 11:47 PM	#11
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	If it works for you, that's cool. I just never understand why people buy big pumps, then choke the flow back. I guess I'm a stickler for efficiency. __________________ - Scott