skimmer not as efficient as it should be

CAbb · 04/12/2008, 10:37 PM

I'm currently running a ER CS6-1 and I'm trying to figure out what I need to change because it's just not running as efficiently as I believe it should. I'm only occasionally getting a watery skimmate in the cup, most of it stop short in the neck. It's definitely skimming, but won't build enough of a foam head to push much into the cup.

I did a recirc mod on it per this forum. My feed pump is kept pretty low so there isn't a massive amount of water flowing into and out of the skimmer. The recirc pump however is a Sedra 5000 and I wonder if it's simply too much pump for this skimmer. There is a meshmod on the pump also and obviously a homemade venturi.

The other question I have is what water level should this particular skimmer be sitting in? It was sitting in several inches of water in my sump and I raised it a few inches but I can't tell a marked difference. I'm wondering if I need to simply have it completely out of water or if there is a max level it should be sitting in?

Thanks in advance!

luke33 · 04/12/2008, 10:43 PM

Water level shouldn't matter if its recirc'd. Pics would help, but imo it doesn't sound like there's enough air being injected into the skimmer. If the foam head is to small, its pry to little air.

CAbb · 04/12/2008, 10:45 PM

what would you suggest is the best way to increase the airflow in that case? I'm pretty limited with physical mods I can make on the skimmer and recir mod at the moment so I'm not sure how I would go about doing that.

A sea K · 04/13/2008, 08:05 AM

The 5000 should be OK especially with the mods and it being a recirc. A 9000 would definitely do the trick but you may run into fitment issues having already drilled the skimmer for the 5000.
I have a 9000 on hand, If you get me the center to center hole dimension on your skimmer I can tell you if it will work if your interested.
I'm running a Sicce PSK2500 on my 8-3 (this little pump rocks BTW), Too much air for your 6-2 IMO but you could dial it back with a valve to tailor your needs. I should also note that this pump is not recommended for external use. However both luke and myself are running ours exposed and I have had no issues.
Agree with luke on the sump depth. Shouldn't matter with a recirc skimmer.

A sea K · 04/13/2008, 08:14 AM

I noticed you said 6-1 not 6-2, what is the diameter and height of your skimmer?
If your using a DIY venturi you should check your air draw with a meter if you haven't already done so. Venturi mods make a big difference in pump performance both good and bad.

CAbb · 04/13/2008, 04:18 PM

this may sound like a silly question, but what would I use (ie what sort of meter) to check my air draw? I will work on getting some dimensions for you.

CAbb · 04/13/2008, 04:56 PM

Alrighty, I got dimensions. The skimmer is 20" tall and has a 6" diameter. HTH

A sea K · 04/13/2008, 07:57 PM

The air meter is from Dwyer intsruments and there are many versions to choose from. I use the RMA-22. It is fine for this application.

The 5000 should be adequate for the skimmer, the 9000 will probably push around too much water with the increased air and create excessive turbulance. It would be OK to try if you already had the pump but not if you had to buy one.

Does the pump seem to be running as good as before you did the mod? The venturi's clog pretty easily, a good cleaning could possibly put you back on track. IDK about your DIY venturi, that could be the problem also.

luke33 · 04/13/2008, 08:02 PM

Wait a sec, after re-reading. What water flowthrough to you have going on with your feed pump? If to little you may have a problem with to low of water level without a gate valve?

Acrocrab · 04/13/2008, 08:17 PM

I have the same skimmer. I did the same mods on it, and it sounds like you have the same problems that I had. I found the problem to be the extra pressure from the body of water above the water line caused too much pressure to enter the pump. So I had to drasticly change the venturi.

All i did was heat up a piece of 1" pvc with a good heat gun then sqeeze it with some pliers while dunking it in cool water so it got hard again.

Then drilled a hole in it for the air tube. I also went with a bigger diameter hose to get more air.

also what kind of mesh did you use? I had to redo mine cause the mesh was too dense.

now it works great.

try it out and see if it works for you!

CAbb · 04/13/2008, 10:27 PM

Quote:

Originally posted by A sea K

The 5000 should be adequate for the skimmer, the 9000 will probably push around too much water with the increased air and create excessive turbulance. It would be OK to try if you already had the pump but not if you had to buy one.

Does the pump seem to be running as good as before you did the mod? The venturi's clog pretty easily, a good cleaning could possibly put you back on track. IDK about your DIY venturi, that could be the problem also.

I was actually told that the 5000 was almost too big for the skimmer and that I should have been running something like a 3500 on it? I've managed to calm the turbulence a lot by putting a T w/ 2 downward facing elbows on the inside of the skimmer where the recirc pump puts the water back into the tank. This helped nominally also because before it was so much turbulence that it was breaking the bubbles up before they could build any sort of head at all.

I may try to get some photos of it this week. It's in a very tiny closed in space so I can't get good photos of it while it's set up. It'll require me taking it apart piece by piece to get it out of the sump under the stand.

Quote:

Originally posted by luke33
Wait a sec, after re-reading. What water flowthrough to you have going on with your feed pump? If to little you may have a problem with to low of water level without a gate valve?

The feed into the pump is pretty low, but I couldn't give you even a guesstimate because it's fed from a manifold which runs several other pieces of equipment. The water level in the skimmer though is kept just below where the neck starts to taper inward on the skimmer.

CAbb · 04/13/2008, 10:35 PM

acrocrab, so you do have a recirc mod drilled into your skimmer? I actually drilled an addiction hole, placed a uniseal into it and am using one of the original holes and the new hole for the recirc pump. The original input for the skimmer is where my other feed pump is running into the skimmer. (I hope all that makes sense).

I'm not sure how I would put a bigger tube into my venturi so when I pull it out this week to take photos I'll have to take a look at that.

Acrocrab · 04/14/2008, 05:36 AM

I drilled a hole in the skimmer just below the orig. hole for the pump to "suck" from. and drilled a smaller hole on the other side 2" higher than the orig. hole for the feed. It works like a bubble rocket! I have to empty the cup every day. i'll work on getting a full pic when I get home from work today.

A sea K · 04/14/2008, 06:44 AM

CAbb,
Clarify the location of your input line from the feed pump in the skimmer body. Your description sounds like you are using the existing factory hole for the main pump. The best location for the feed is the upper 2/3 of the body, the lower you go from that point the less efficient the skimmer becomes. Basically the incoming water just exits the skimmer before it has a chance to get processed.

I still think the 5000 should work good if your mod was successful. The more air you can get the pump to pull the less water it pushes. The label on my 5000 give it a max flow of 500 gph without air.

The info you give indicates the venturi is the main part of the problem but it is difficult to be certain without seeing the skimmer in action. The air meter will be very helpful in determining how effective your venturi is. Are there any reefers near you that may have a meter you can borrow?

For refernce,I checked the ER site and they list the 5000 at 660-720lph . This is 11-12 lpm on the dweyer rma-22 meter.

orangekush4 · 04/14/2008, 07:30 AM

The problem is,20" tall skimmer well not work good as a RC skimmer.The 5000 might be to strong.

Acrocrab · 04/14/2008, 08:00 PM

Cabb, yah i've got the redirect on it too. And I had alot of issue's with it. I had to tinker with it for some time to get it right. I really think you can get away with using the 5000. Its going to come down to the venturi. Your going to have to build it with the smallest possible appiture to limit the incoming water to max out the amount of air it can pull. Otherwise you may have too much flow through with the 5000 plus a feed pump. As far as it only being 20" tall you're right to a point. There was alot of turbulence before i re-did the venturi. now it has smoothed out. Then again I only use the 3500.

Here are the photos I promised
the redirect pluming

the feed input

CAbb · 04/15/2008, 10:40 PM

thank you for the pictures.

As for mine, I"m going to have to redo it anyhow...the pump crapped out on me tonight so I need to find another sedra 5000.

As for the feed, it is towards the upper 2/3rd's of the skimmer body.

Once I find a new pump I'll revisit those pics you gave me here and see about redoing the venturi. Because I'm limited on space in my sump, the pump actually sits upside down right next to the skimmer rather than out like yours (does that make sense?)

CAbb · 04/15/2008, 10:55 PM

I just pulled the skimmer and pump completely out of the tank and I just realized that it's not even a sedra pump. It's a dolphin dp800. They are pretty similar but I don't know how that one got past me. I'm wondering though if the sedra is a better pump? Since now I'm going to have to buy another one? Any input?

04/12/2008, 10:37 PM	#1
CAbb Registered Member Join Date: Nov 2007 Posts: 53	skimmer not as efficient as it should be I'm currently running a ER CS6-1 and I'm trying to figure out what I need to change because it's just not running as efficiently as I believe it should. I'm only occasionally getting a watery skimmate in the cup, most of it stop short in the neck. It's definitely skimming, but won't build enough of a foam head to push much into the cup. I did a recirc mod on it per this forum. My feed pump is kept pretty low so there isn't a massive amount of water flowing into and out of the skimmer. The recirc pump however is a Sedra 5000 and I wonder if it's simply too much pump for this skimmer. There is a meshmod on the pump also and obviously a homemade venturi. The other question I have is what water level should this particular skimmer be sitting in? It was sitting in several inches of water in my sump and I raised it a few inches but I can't tell a marked difference. I'm wondering if I need to simply have it completely out of water or if there is a max level it should be sitting in? Thanks in advance!

04/13/2008, 08:05 AM	#4
A sea K Registered Member Join Date: Sep 2006 Location: Branford Fl Posts: 3,024	The 5000 should be OK especially with the mods and it being a recirc. A 9000 would definitely do the trick but you may run into fitment issues having already drilled the skimmer for the 5000. I have a 9000 on hand, If you get me the center to center hole dimension on your skimmer I can tell you if it will work if your interested. I'm running a Sicce PSK2500 on my 8-3 (this little pump rocks BTW), Too much air for your 6-2 IMO but you could dial it back with a valve to tailor your needs. I should also note that this pump is not recommended for external use. However both luke and myself are running ours exposed and I have had no issues. Agree with luke on the sump depth. Shouldn't matter with a recirc skimmer. __________________ I am not a pro so excuse me if I'm wrong. Current Tank Info: 30gal Deep Blue rimless 9/10/2014, 80gal Deep Blue rimless 40gal sump/refugium 9/11/16 LPS reef, 2 x Kessil A160 with a single Maxspect Razor, RO Prime 150INT skimmer, Sicce 3 return pump, Vortech MP40 and MP10

04/13/2008, 08:14 AM	#5
A sea K Registered Member Join Date: Sep 2006 Location: Branford Fl Posts: 3,024	I noticed you said 6-1 not 6-2, what is the diameter and height of your skimmer? If your using a DIY venturi you should check your air draw with a meter if you haven't already done so. Venturi mods make a big difference in pump performance both good and bad. __________________ I am not a pro so excuse me if I'm wrong. Current Tank Info: 30gal Deep Blue rimless 9/10/2014, 80gal Deep Blue rimless 40gal sump/refugium 9/11/16 LPS reef, 2 x Kessil A160 with a single Maxspect Razor, RO Prime 150INT skimmer, Sicce 3 return pump, Vortech MP40 and MP10

04/13/2008, 07:57 PM	#8
A sea K Registered Member Join Date: Sep 2006 Location: Branford Fl Posts: 3,024	The air meter is from Dwyer intsruments and there are many versions to choose from. I use the RMA-22. It is fine for this application. The 5000 should be adequate for the skimmer, the 9000 will probably push around too much water with the increased air and create excessive turbulance. It would be OK to try if you already had the pump but not if you had to buy one. Does the pump seem to be running as good as before you did the mod? The venturi's clog pretty easily, a good cleaning could possibly put you back on track. IDK about your DIY venturi, that could be the problem also. __________________ I am not a pro so excuse me if I'm wrong. Current Tank Info: 30gal Deep Blue rimless 9/10/2014, 80gal Deep Blue rimless 40gal sump/refugium 9/11/16 LPS reef, 2 x Kessil A160 with a single Maxspect Razor, RO Prime 150INT skimmer, Sicce 3 return pump, Vortech MP40 and MP10

04/14/2008, 06:44 AM	#14
A sea K Registered Member Join Date: Sep 2006 Location: Branford Fl Posts: 3,024	CAbb, Clarify the location of your input line from the feed pump in the skimmer body. Your description sounds like you are using the existing factory hole for the main pump. The best location for the feed is the upper 2/3 of the body, the lower you go from that point the less efficient the skimmer becomes. Basically the incoming water just exits the skimmer before it has a chance to get processed. I still think the 5000 should work good if your mod was successful. The more air you can get the pump to pull the less water it pushes. The label on my 5000 give it a max flow of 500 gph without air. The info you give indicates the venturi is the main part of the problem but it is difficult to be certain without seeing the skimmer in action. The air meter will be very helpful in determining how effective your venturi is. Are there any reefers near you that may have a meter you can borrow? For refernce,I checked the ER site and they list the 5000 at 660-720lph . This is 11-12 lpm on the dweyer rma-22 meter. __________________ I am not a pro so excuse me if I'm wrong. Current Tank Info: 30gal Deep Blue rimless 9/10/2014, 80gal Deep Blue rimless 40gal sump/refugium 9/11/16 LPS reef, 2 x Kessil A160 with a single Maxspect Razor, RO Prime 150INT skimmer, Sicce 3 return pump, Vortech MP40 and MP10 Last edited by A sea K; 04/14/2008 at 06:53 AM.

04/12/2008, 10:43 PM	#2
luke33 Moved On Join Date: Dec 2006 Location: Indiana Posts: 8,375	Water level shouldn't matter if its recirc'd. Pics would help, but imo it doesn't sound like there's enough air being injected into the skimmer. If the foam head is to small, its pry to little air.

04/12/2008, 10:45 PM	#3
CAbb Registered Member Join Date: Nov 2007 Posts: 53	what would you suggest is the best way to increase the airflow in that case? I'm pretty limited with physical mods I can make on the skimmer and recir mod at the moment so I'm not sure how I would go about doing that.

04/13/2008, 04:18 PM	#6
CAbb Registered Member Join Date: Nov 2007 Posts: 53	this may sound like a silly question, but what would I use (ie what sort of meter) to check my air draw? I will work on getting some dimensions for you.

04/13/2008, 04:56 PM	#7
CAbb Registered Member Join Date: Nov 2007 Posts: 53	Alrighty, I got dimensions. The skimmer is 20" tall and has a 6" diameter. HTH

04/13/2008, 08:02 PM	#9
luke33 Moved On Join Date: Dec 2006 Location: Indiana Posts: 8,375	Wait a sec, after re-reading. What water flowthrough to you have going on with your feed pump? If to little you may have a problem with to low of water level without a gate valve?

04/13/2008, 08:17 PM	#10
Acrocrab Registered Member Join Date: Jan 2008 Location: hemet, Ca Posts: 14	I have the same skimmer. I did the same mods on it, and it sounds like you have the same problems that I had. I found the problem to be the extra pressure from the body of water above the water line caused too much pressure to enter the pump. So I had to drasticly change the venturi. All i did was heat up a piece of 1" pvc with a good heat gun then sqeeze it with some pliers while dunking it in cool water so it got hard again. Then drilled a hole in it for the air tube. I also went with a bigger diameter hose to get more air. also what kind of mesh did you use? I had to redo mine cause the mesh was too dense. now it works great. try it out and see if it works for you!

04/13/2008, 10:35 PM	#12
CAbb Registered Member Join Date: Nov 2007 Posts: 53	acrocrab, so you do have a recirc mod drilled into your skimmer? I actually drilled an addiction hole, placed a uniseal into it and am using one of the original holes and the new hole for the recirc pump. The original input for the skimmer is where my other feed pump is running into the skimmer. (I hope all that makes sense). I'm not sure how I would put a bigger tube into my venturi so when I pull it out this week to take photos I'll have to take a look at that.

04/14/2008, 05:36 AM	#13
Acrocrab Registered Member Join Date: Jan 2008 Location: hemet, Ca Posts: 14	I drilled a hole in the skimmer just below the orig. hole for the pump to "suck" from. and drilled a smaller hole on the other side 2" higher than the orig. hole for the feed. It works like a bubble rocket! I have to empty the cup every day. i'll work on getting a full pic when I get home from work today.

04/14/2008, 07:30 AM	#15
orangekush4 Registered Member Join Date: Feb 2005 Posts: 367	The problem is,20" tall skimmer well not work good as a RC skimmer.The 5000 might be to strong.

04/14/2008, 08:00 PM	#16
Acrocrab Registered Member Join Date: Jan 2008 Location: hemet, Ca Posts: 14	Cabb, yah i've got the redirect on it too. And I had alot of issue's with it. I had to tinker with it for some time to get it right. I really think you can get away with using the 5000. Its going to come down to the venturi. Your going to have to build it with the smallest possible appiture to limit the incoming water to max out the amount of air it can pull. Otherwise you may have too much flow through with the 5000 plus a feed pump. As far as it only being 20" tall you're right to a point. There was alot of turbulence before i re-did the venturi. now it has smoothed out. Then again I only use the 3500. Here are the photos I promised the redirect pluming the feed input

04/15/2008, 10:40 PM	#17
CAbb Registered Member Join Date: Nov 2007 Posts: 53	thank you for the pictures. As for mine, I"m going to have to redo it anyhow...the pump crapped out on me tonight so I need to find another sedra 5000. As for the feed, it is towards the upper 2/3rd's of the skimmer body. Once I find a new pump I'll revisit those pics you gave me here and see about redoing the venturi. Because I'm limited on space in my sump, the pump actually sits upside down right next to the skimmer rather than out like yours (does that make sense?)

04/15/2008, 10:55 PM	#18
CAbb Registered Member Join Date: Nov 2007 Posts: 53	I just pulled the skimmer and pump completely out of the tank and I just realized that it's not even a sedra pump. It's a dolphin dp800. They are pretty similar but I don't know how that one got past me. I'm wondering though if the sedra is a better pump? Since now I'm going to have to buy another one? Any input?