Octopus Skimmer Mods

[davidabrown66]

Originally posted by jbeltmann
When doing the mesh mod would fishing line be better than zip ties? I have found some pumps don't like the altered balance when using zip ties and was thinking fishing line might be a better option in that aspect. What do you guys think?

I use 10 Lb test fishing line, it works great

[hng]

Just got my nw200 yesterday and wanted to do the gate valve mod. Anyone have a parts list with the sizes?

[squin]

My best results came from removing one needle wheel from a new, smaller impeller and breaking off half the pins on the second needle wheel. I cut 3 layers of Enkamat to the diameter of the larger, older impeller ( 2-1/4") and secured using fishing line. After securing the mesh with individual knots to each remaining pin I wove a second length of fishing line around the outside perimeter of the mesh to insure it was the same thickness of the mesh secured directly to the pins.

[carlos_fb]

Originally posted by hng
Just got my nw200 yesterday and wanted to do the gate valve mod. Anyone have a parts list with the sizes?

If the plumbing of the 200 is the same as the 150, you need to make it 1 1/4". All you need is a gate valve, 1 T, 1 elbow, a coupler and of course a few pieces of pvc to put it together. If you want I can get few pictures for you.

Good luck!

[Mr Bojangles]

here is the pics of gate valve on my 200, the coupler is just sanded down on the inside to fit over the riser tube so I did not have to cut is or glue it.

[markywmson]

the plumbing of the 200 is larger than the 150. i used 1 1/2" plumbing and 1 1/2" to 1 1/4" rubber boot to come from the riser tube to my gate valve. it took some work and dipping the boot in boiling water to get it to expand, but it seals REALLY nicely now. good luck!

[squin]

I was tinkering with my skimmer and removed the airflow meter to clean it. Wow! Even after cleaning the meter the results were the same. Without the restriction of the Dwyer MMA-7 the airflow increased, turbulence in the skimmer chamber dropped, and the wattage dropped. 18 watts to 77. I shouldn't be surprised, but the results were dramatic. Without the meter it was blowing the top off the collection cup. I had to open the ball valve and lower the water level to collect the desired, thick foam.

The lesson learned here for me was that while these meters are essential to determining the impact of our various mods, once we settle into a particular setup we should probably run without the airflow meter. The restriction of my meter was definitely holding my skimmer back. I can only guess what the airflow is now! Other more expensive meters probably offer less restriction, but I don't think I want to spend the coin to try different meters.

[charlesjordanjr]

Originally posted by davidabrown66
I've had my DNW-200 for about 3 months now, and I ordered another pump as a spare. Both have the newer and smaller diameter impeller

hmm.. Igot a replacement impeller from custom aquatic in april. It was the old one. I just got another impeller to play with form marinesolutionsinc and it is the smaller one. I guess I will gove the gutter guard a try.
-Chuck

[hng]

Just measured the output tube on my nw200 and it is almost 2 inches in diameter. Is it bigger now or am I missing something (previous suggestions to use 1 1/2 in pvc). What size gate valce should I use with the nw200?

[carlos_fb]

Going back to the gate valve mod, is it me or it actually makes the skimmer harder to control and extremely sensitive to any variation in the water level?

[outy]

WOOT

just finished my second pump 34-scfh and my first mod after stopping and restarting is 31-scfh for a total of

65-scfh

now i just wonder if the 4" neck can handle that much air?

these skimmers rock

[davidabrown66]

Originally posted by squin
My best results came from removing one needle wheel from a new, smaller impeller and breaking off half the pins on the second needle wheel. I cut 3 layers of Enkamat to the diameter of the larger, older impeller ( 2-1/4") and secured using fishing line. After securing the mesh with individual knots to each remaining pin I wove a second length of fishing line around the outside perimeter of the mesh to insure it was the same thickness of the mesh secured directly to the pins.

Squin, I just did the same thing this weekend although I still have all my pins on my lower NW. It's performing better with better water circulation at the cost of wattage. I'm now at 92 watts, so I see where your high wattage is coming from, but oddly it didn't change my SCFH, it's still around 21. I am getting a forest green looking gunk though which is promising.

Do you know if there's a difference in the stock air draw between the OTP-3000, OR3500, or OR3700? I'm thinking about switching pumps to an OR3700 or using the OR3700 impeller if there is.

[davidabrown66]

Originally posted by outy
WOOT

just finished my second pump 34-scfh and my first mod after stopping and restarting is 31-scfh for a total of

65-scfh

now i just wonder if the 4" neck can handle that much air?

these skimmers rock

This is on a DDNW-250 right? I think that'll max it out for sure. Isn't that like 2000 LPH of air?

OK, now I'm really jealous! Any changes to your pump/impeller mods to get to 34 SCFH? I can't believe the performance you're getting....luucky.

[outy]

yep ddnw 250 its about 1500

overnight its jumped to 35 on one and 31 on the other

total mod time was about an hour

thanks to all the good reading here and info i went straight to it.

the only difference between the two mods could be the application of enkamat im using 4 zipties and trimming diameter and hieght so it wont hit where the water comes in. both mods were the same. [the poofyness of the pf4 is the only thing different, its hard to get the same without samwiching the material with GG]

ive maxed the skimmer and i think its to much air where can i find reading to tune this nin or learn about neck sizes???

[davidabrown66]

Originally posted by outy
yep ddnw 250 its about 1500

overnight its jumped to 35 on one and 31 on the other

total mod time was about an hour

thanks to all the good reading here and info i went straight to it.

the only difference between the two mods could be the application of enkamat im using 4 zipties and trimming diameter and hieght so it wont hit where the water comes in. both mods were the same. [the poofyness of the pf4 is the only thing different, its hard to get the same without samwiching the material with GG]

ive maxed the skimmer and i think its to much air where can i find reading to tune this nin or learn about neck sizes???

So, you're using GG as well?

You can use an air valve on the air input to dial it down some, that's what others have done.

[davidabrown66]

Outy, you also mentioned in your mod that you are using a JG fitting instead of the nipple like Roland. Just to clarify, are you using a 3/8" threaded JG fitting?

And when you say it has the diameter of ro tubing, is the airway large enough to insert RO tubing at both ends? In other words, does it have an OD or ID of RO tubing ie 1/4" or 1/8"?

You're also NOT drilling all the way through into the waterway and retaining the original 90 deg bend of the airway. Is that right?

[squin]

Originally posted by davidabrown66
Squin, I just did the same thing this weekend although I still have all my pins on my lower NW. It's performing better with better water circulation at the cost of wattage. I'm now at 92 watts, so I see where your high wattage is coming from, but oddly it didn't change my SCFH, it's still around 21. I am getting a forest green looking gunk though which is promising.

Do you know if there's a difference in the stock air draw between the OTP-3000, OR3500, or OR3700? I'm thinking about switching pumps to an OR3700 or using the OR3700 impeller if there is.

I don't have any info on using the OR3700 as a replacement for the OTP-3000, but I understand it should work as a replacement. Based on what I read it should be about the same performance if not identical. If anyone has tried this, and can confirm that the pump inlet/outlet are the same, I would like to hear about it.

[Bunkerbean]

I was going to do a gate valve mod on me NW-150. Does anyone know what size of pipe is takes?

[davidabrown66]

Originally posted by squin
I don't have any info on using the OR3700 as a replacement for the OTP-3000, but I understand it should work as a replacement. Based on what I read it should be about the same performance if not identical. If anyone has tried this, and can confirm that the pump inlet/outlet are the same, I would like to hear about it.

Refresh my memory, you're using the RPS-3000? If so, does that use the OR3700? Do you have metric unions on the RPS-3000?

I'm seeing from the specs given too me that the OR3700 is more closely related to the Eheim 1260/1262, but I thought the OR3700 was just the OR3500 with a nw and input/output preplumbed for the Aquamedic T5000 specifically?

Also, the OR3500 is rated for 900 gph, and the OTP-3000 moves 750 gph (3000 LPH).

Outy is able to get 30+ SCFH on both of his OTP-3000's which repoints me back to the venturi and nw design and mods.

[BLockamon]

The OR3700 does NOT have the same inlet/outlet as the OTP-3000. The inlet is the same, but the outlet is much larger on the OR3700. The OR3500 has the same inlet/outlet as the OTP-3000 and is a drop-in replacement (no needlewheel though).

[squin]

Originally posted by davidabrown66
Refresh my memory, you're using the RPS-3000? If so, does that use the OR3700? Do you have metric unions on the RPS-3000?

I'm seeing from the specs given too me that the OR3700 is more closely related to the Eheim 1260/1262, but I thought the OR3700 was just the OR3500 with a nw and input/output preplumbed for the Aquamedic T5000 specifically?

Also, the OR3500 is rated for 900 gph, and the OTP-3000 moves 750 gph (3000 LPH).

Outy is able to get 30+ SCFH on both of his OTP-3000's which repoints me back to the venturi and nw design and mods.

I have the OTP-3000 running on an RPS-3000, and unfortuantely it does have the metric unions. Based on the post I just read above it looks like we could use the OR3500, but would have to swap out the impeller. I also noticed that the OR3700 is stock with a larger output which is one of the mods we have done.

Next question is are the impellers for the OR3700 and the OTP-3000 different? If so, how? Would be nice to be able to drop an OTP-3000 impeller into a OR3500. Then again you'd probably end up with an OTP-3000 clone, or vice-versa.

[squin]

Originally posted by outy
yep ddnw 250 its about 1500

overnight its jumped to 35 on one and 31 on the other

total mod time was about an hour

thanks to all the good reading here and info i went straight to it.

the only difference between the two mods could be the application of enkamat im using 4 zipties and trimming diameter and hieght so it wont hit where the water comes in. both mods were the same. [the poofyness of the pf4 is the only thing different, its hard to get the same without samwiching the material with GG]

ive maxed the skimmer and i think its to much air where can i find reading to tune this nin or learn about neck sizes???

Outy,

Nice results! I know my one modded OTP-3000 is just about all the skimmer neck can handle. Are you having to dial back the air with both pumps running? What kind of wattage are you reading?

[carlos_fb]

Originally posted by Bunkerbean
I was going to do a gate valve mod on me NW-150. Does anyone know what size of pipe is takes?

You have to make it 1 1/4".

[carlos_fb]

Originally posted by carlos_fb
Going back to the gate valve mod, is it me or it actually makes the skimmer harder to control and extremely sensitive to any variation in the water level?

Anybody?

[hounddog01]

Originally posted by carlos_fb
Anybody?

I do not have the gate valve mod because I was cheap and did not want to spend the $20.00 for the valve. My whole mod cost less than $5.00. Now normaly I am not that cheap but this has worked very nicely without actually modifing the skimmer. I used 2 inch PVC and was able to find a pressure fitting that sliped over the pipe and tightened down to prevent leaking but still loose enough to move up and down.

For $5.00 you may want to try it.