Octopus Skimmer Mods

[mr. pluto]

squin, THE OR3700'S have 4 sets of spokes but no pins
the replacement wheel has 2 sets of spokes & pins just like the
original part, but smaller by about .5 dia.

[areze]

is there a condensed mod list to make an octopus skimmer better? sorry for being lazy but theres about 500 pages of threads discussing mods, any long story short of what works?

[squin]

Originally posted by mr. pluto
squin, THE OR3700'S have 4 sets of spokes but no pins
the replacement wheel has 2 sets of spokes & pins just like the
original part, but smaller by about .5 dia.

Thanks Pluto,

For future reference can an OR3700 be used as a replacement for a OTP3000? Are the inlet and outlet fittings and other pump dimensions the same?

[outy]

areze first

the o-ring mod, air is blocked from the gasket on the venturi. use a o-ring instead of the gasket

venturi mod, not enough air can pass through the venturi so its drilled out to the i\d size of 1/4" ro/di rigid tubing [or larger]

mesh mod, get some enkamat pf4 add 3 layers after breaking of the top arms\pins on your impeller. use fishing line or small zipties to attach.

output mod, drill out the output with a 5/8 spade bit so that the water can flow easier and suck more air

all of these mods have different ways of going to the extreme if you choose to do so.

please feel free to add to this incase i missed something


im hoping this is all the same for recirc models as well

[mr. pluto]

squin, it works
but not as good as the original.

[davidabrown66]

Ok, I had to look at the pump pics again, and I see that I my nw's look like the ones on the right, but have a smaller diameter like the ones on the left.

I'll try the hose gasket on the input side of the venturi, and see what that does.

I'll also check with Champion and see if they have the venturi's.

Thanks all!

[Bunkerbean]

So was going to do some mods on the pump. I drilled out the nipple and air intake. One thing I noticed it there was no gasket in the venturi part. I wonder if they changed this from earlier models?

I will have to take some pictures tonight.

Still waiting on the mess to show up.

[davidabrown66]

Originally posted by Bunkerbean
So was going to do some mods on the pump. I drilled out the nipple and air intake. One thing I noticed it there was no gasket in the venturi part. I wonder if they changed this from earlier models?

I will have to take some pictures tonight.

Still waiting on the mess to show up.

I've used mine without the gasket. If you find it still leaks then go to lowes and get one. I think they're the #18.

[Bunkerbean]

Is the gasket really thin? There in not a lot of room between the air hole and the threads.

I will look for the gasket next time I am HD.

[squin]

Originally posted by davidabrown66
Ok, I had to look at the pump pics again, and I see that I my nw's look like the ones on the right, but have a smaller diameter like the ones on the left.

I'll try the hose gasket on the input side of the venturi, and see what that does.

I'll also check with Champion and see if they have the venturi's.

Thanks all!

Don't bother. I just received the wrong part for the 3rd time. I'm very frustrated at this point with trying to get a replacement venturi.

[davidabrown66]

Originally posted by Bunkerbean
Is the gasket really thin? There in not a lot of room between the air hole and the threads.

I will look for the gasket next time I am HD.

Yes, it's a rubber ring gasket, there are pics on this thread some where

[davidabrown66]

Originally posted by squin
Save your time. I just received the wrong part for the 3rd time. Very frustrated at this point with trying to get a replacement venturi.

No way! I'm sorry to hear that, I was just about to call them.

I have a call into aquacave and customaquatics for one, but it doesn't sound like they'll have them in for a couple of weeks.

Both aquacave and customaquatics have said that Coralvue is extremely hard to get a hold of, and I've even called them and left a message, and they never returned my call either. As a side note, I've called premiumaquatics who also sell them, but they only carry the impeller.

[Bunkerbean]

Thanks. I remember the picuture. Just looks a little decieving in person.


Just wanting to make sure I am doing it right.

[davidabrown66]

Originally posted by Bunkerbean
Thanks. I remember the picuture. Just looks a little decieving in person.


Just wanting to make sure I am doing it right.

The gasket doesn't overlap at all, but I would open up the hole a little anyway with a little larger drill bit.

[Bunkerbean]

Would there be a problem with totally reaming out the bottom of the hole?

[davidabrown66]

Originally posted by Bunkerbean
Would there be a problem with totally reaming out the bottom of the hole?

That's what I ended up doing when I reamed out the venturi waterway with 5/8" spade bit, but i think that actually lowered my SCFH #'s when I increase my waterflow.

[squin]

Originally posted by squin
On another note... Just for giggles I reduced the water flow through the venturi by placing a standard, garden hose washer on the inlet side of my venturi. kroe mentioned reducing water flow earlier, and I wanted to experiment with reducing the water flow when using my mesh modded impellar. The results were positive, 26 SCFH (very steady, no bouncing ball) and 107 Watts. This is a positive for me because I was pulling ~ 25 SCFH and 126 Watts without the reduced water flow. Once I get the replacement venturi I will try the RO tubing mod that you and others have had success with.

Maybe you can try a garden hose washer on your reemed out venturi. It's a very simple mod and its reversible. I just pressed the flexible rubber washer into the inlet of the venturi where it tapers in. I'm hoping it could decrease water flow and increase air flow. Let me know your results if you try.

Still shooting for 25 - 30 SCFH and 65 Watts!

Here's a couple of shots of the garden hose washer in my venturi.



Venturi Inlet



Venturi Outlet

You can see that the rubber washer slightly reduces the opening. The only other mods to this venturi are the notched gasket so it does not block the airway, and enlarged the existing airway to 11/64" without drilling straight through.

[Bunkerbean]

Ok well maybe with mine not reamed out to 5/8" maybe I will have good air flow.

[davidabrown66]

Originally posted by Bunkerbean
Ok well maybe with mine not reamed out to 5/8" maybe I will have good air flow.

That's what I'm planning on doing if I can get another venturi ordered somewhere. I'm going to try the hose gasket tonight on the reamed one anyway just to see if increases my air flow.

[davidabrown66]

Originally posted by squin
Here's a couple of shots of the garden hose washer in my venturi.



Venturi Inlet



Venturi Outlet

You can see that the rubber washer slightly reduces the opening. The only other mods to this venturi are the notched gasket so it does not block the airway, and enlarged the existing airway to 11/64" without drilling straight through.

Thanks for the pics, this really helps!

[davidabrown66]

Squin, did you drill the venturi nipple to 11/64" as well?

[squin]

Originally posted by davidabrown66
Squin, did you drill the venturi nipple to 11/64" as well?

Yes, I drilled the entire airway to 11/64". I started with smaller bits and worked my way up to 11/64" I accidentally drilled straight through when enlarging the nipple airway, but I later plugged the hole with CA. You may try placing the butt end of another drill bit into the 90 deg airway so you don't drill all the way through. I didn't document it, but I believe I got better results maintaing the existing airway without the straight through hole. Go slow so you don't crack the nipple.

I'm currently running 26 SCFM at 91 watts. If I can ever get my hands on a replacement venturi I will attempt to enlarge the airway a little more until I reach my goal of 30 SCFM at 65 Watts, or I break the nipple. At that point I will try the RO tubing mods you guys have done.

[outy]

i did the jg 1/4 tubing mod like roland. and drilled everything out the same size as the id of the tubing.

the only thing i did different is i drilled with a smaller bit then he did [where the original air nipple was and ground the jg fitting threads down/off so it would fit in the smaller hole and then epoxied that in before reaming the air hole out on the o-ring side

[tikalize]

I would like to mesh mod my impeller on my NW-200. Anyone have any enkmat that i could buy or what material is better? If not please point me in the right direction to purchase some. Thanks..

[outy]

ebay 5.50 free shipping just do a search for enkamat pf4