Octopus Skimmer Mods
- Thread starter JohnL
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ppurcell
New member
JC, after a week of break-in using my un-modded needle wheel with 4 layers of Enkamat wiretied to it I am now getting 15 lpm (31.8 scfh) and the watts have dropped to about 73-74.
I was going to tear my impeller apart yesterday so I could put it together the way you described yours, but decided that it is doing just about what I had hoped for all along. The only downside I see right now, is that A) I might be able to reduce the power draw but to go from 73 watts to 60 watts would result in a savings of 69 cents per month so I'm not going to sweat that too much. B) I imagine that I might be able to increase the air input to 16+ or more lpm as you said should be possible in your post.
I was going to tear my impeller apart yesterday so I could put it together the way you described yours, but decided that it is doing just about what I had hoped for all along. The only downside I see right now, is that A) I might be able to reduce the power draw but to go from 73 watts to 60 watts would result in a savings of 69 cents per month so I'm not going to sweat that too much. B) I imagine that I might be able to increase the air input to 16+ or more lpm as you said should be possible in your post.
reefez
New member
I need Enkamat too if anyone has any? I am happy witht he GG mod but I think I want to experiment with the Enkamat. I am now feeding the skimmer with one of my overflow lines. Is their a downside to only useing 1 overflow hose to feed the skimmer or should I try and connect the two and have them both run into the skimmer? As it is I had to put a shut off valve en-route to the skimmer to reduce the flow to the desired flow of 150 gph. I also drilled out the venturi straight down, and reamed out the 90 degree hole a bit too. I don't have a meter to see how much air it is pulling, but I know it is more then it was out of the box. The air line now sticks to my finger without falling off LOL. 
I love this skimmer! It is only on it's 3rd day and in 24 hrs. on it's second day it pumped out 1 cup of mud.
I love this skimmer! It is only on it's 3rd day and in 24 hrs. on it's second day it pumped out 1 cup of mud.
ReefLurker
Premium Member
Would someone point me in the direction of where I could purchase an air flow meter? Thanks, Jeff
ppurcell
New member
http://www.dwyer-inst.com/htdocs/flow/SeriesRMPrice.cfm
Probably look to these models: (or comparible w/ss valve)
2" - RMA-7, RMA-22, RMA-23 ($24)
5" - RMB-52, RMB-52D, RMB-53D ($36)
10" - RMC-101, RMC-102 ($70)
Personally, I would lean towards thr RMB-53D keeping in mind that small pumps may only draw 5 lpm or less out of the box which is the bottom of the scale. The 2" scale is probably too small and others have said that the 10" scale is more stable, but it is quite a bit more expensive too.
Here is a page that can be used to convert different units of measure:
http://www.flowlineoptions.com/tools.html
A(nother) quick search on eBay showed me a RMB-52D-SSV for $35, a RMB-52 for $30, two RMB-53's for $15
Probably look to these models: (or comparible w/ss valve)
2" - RMA-7, RMA-22, RMA-23 ($24)
5" - RMB-52, RMB-52D, RMB-53D ($36)
10" - RMC-101, RMC-102 ($70)
Personally, I would lean towards thr RMB-53D keeping in mind that small pumps may only draw 5 lpm or less out of the box which is the bottom of the scale. The 2" scale is probably too small and others have said that the 10" scale is more stable, but it is quite a bit more expensive too.
Here is a page that can be used to convert different units of measure:
http://www.flowlineoptions.com/tools.html
A(nother) quick search on eBay showed me a RMB-52D-SSV for $35, a RMB-52 for $30, two RMB-53's for $15
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ReefLurker
Premium Member
Thanks!
reefez
New member
Hey I'm modding my pump further tomorrow. I am gojng to basically do all of them. What is the black air thingy that connects to the end of the venturi line? And are all of you useing it? I had left mine off, but found it skims a little better with it on. Seems like it get's more air which I don't understand because the other hole that the air is sucked through is smaller then the actual venturi line.
hounddog01
Active member
Sometimes the pump is not pulling enough water to create the maximum suction of air. By reducing the amount of air, this increases the amount of water, which increases the amount of air.
I know it does not make much sence but it does work.
reefez
New member
So by boaring out the intake and valute output you increase the water flow through the pump. Then if you do the venturi mod and throw some gutter guard or mesh on the impeller you increase the air. So now you have more of both. Water flow, and air suction. Bot if it's pulling too much air you restrict it by putting the black thing on the end of the venturi right?
JCTewks
In Memoriam
that way you can fine tune your skimmer with the air valve. i am using a dwyer air meter with a valve on it. running it wide open A) produces too much air for my skimmer. B) make sfor larger bubbles. and C) it just doesn't perform as well without it.
Before I had the Dwyer i just used a needle valve like you'd find going to the ice maker on your fridge...worked great!
Before I had the Dwyer i just used a needle valve like you'd find going to the ice maker on your fridge...worked great!
After doing a pump outlet mod (to 1" PVC) and a recirc mod on my NW-200 the wattage went through the roof - from typical 65 watts to 90. The air flow went way up, but with it went the water flow; there was lots of turbulence in the skimmer body.
After lots of tinkering and a tip from RichConley, I found the problem - the venturi! I was using a 1" pipe with a 3/4" pipe inside it with a hole drilled for a JG fitting. The inner pipe's opening was too big - I made a new venturi that tapered down from 1" to 1/2" with the air line coming in on the pump side of the venturi right where the narrow part starts to taper out wider. The air flow went up even more (not sure how much more yet, since my meter is pegged at 25 scfh - bigger one on the way), but most importantly the water flow plummetted and with it the wattage. It is now running at 58 watts and there is almost no turbulence in the skimmer body.
After lots of tinkering and a tip from RichConley, I found the problem - the venturi! I was using a 1" pipe with a 3/4" pipe inside it with a hole drilled for a JG fitting. The inner pipe's opening was too big - I made a new venturi that tapered down from 1" to 1/2" with the air line coming in on the pump side of the venturi right where the narrow part starts to taper out wider. The air flow went up even more (not sure how much more yet, since my meter is pegged at 25 scfh - bigger one on the way), but most importantly the water flow plummetted and with it the wattage. It is now running at 58 watts and there is almost no turbulence in the skimmer body.
reefez
New member
Seems to me like too much modding needs to be done to these skimmers to perform well. I'm takeing off the gutter guard and putting on mesh pad that I got from the Home Depot. I am also going to boar out the valute, and the intake a bit. I guess I might as well re-do the venturi too. Shoot how about I just re-design the entire thing? Oh wait a minute. That's what I'm doing.
I can not for the life of me get this thing to skim dry. Is that because their is not enough air getting into the skimmer? If these mods don't work I'm putting it up for sale and getting a H&S or Euroreef. I'm just worried if I do all the modding that I will be getting too much air-water, and won't be able to go back.
I can not for the life of me get this thing to skim dry. Is that because their is not enough air getting into the skimmer? If these mods don't work I'm putting it up for sale and getting a H&S or Euroreef. I'm just worried if I do all the modding that I will be getting too much air-water, and won't be able to go back.
reefez
New member
Also I allready have the 3000 so it is a recirc that basically just skims wet out of the box. Someone tell me I diden't just blow 400.00 on a junk skimmer. I have read through this thread, and have done the gg mod. Should I drill out the venturi and glue the r/o tubeing in? I mean it's the same diamater hose that's on their right now so what good is that? Just because you are eliminateing the 90 degree elbow?
Reefez, just last page you were praising this thing for how great it was, and now you bash it?
My octopus took upwards of 2 weeks before it became stable, another couple of weeks before it was really performing.
Stop tweaking and let it run for awhile, it's easy to get discouraged.
My octopus took upwards of 2 weeks before it became stable, another couple of weeks before it was really performing.
Stop tweaking and let it run for awhile, it's easy to get discouraged.
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