Reef Octopus Pump Upgrade

[davidabrown66]

Received my new Gen-x 4100 last night, and only had time to test the SCFH with the Euroreef NW, volute and venturi. I measured 18 SCFH after doing that which seems a little lower than expected, but then again I have to add mesh still. Which leads me to the next question.

How do I mesh the ER needle wheel? I've done the OTP many times, and this one is completely different. Do I cut all the pins off or most? Do I drill into the disk that the pins are connect to in order to secure with wire ties?

I won't have time to finish the mod and test it until next week since I'm going out of town tomorrow.

Anyone have a link to pics of this mod would be appreciated. I'd hate to mess up a $65 impeller.

Thanks,

 

[davidabrown66]

So, I tried 3 layers of mesh after snipping off all the small nw's of the er impeller and leaving the larger ones to keep the mesh from slipping. I'm now getting 22 SCFH, but I think the pump is cavitating, b/c the output is weak, and pump is extremely noisy.

Overall, very disappointing from what I thought was going to be 900 LPH stock using the ER NW, volute and venturi. I'll have to cut back on the mesh, and see if I can improve the #'s. I did try and restrict the air input by using ro line inserted into the 3/8" airline, but that didn't do anything. The pump is sitting in a 5 gal bucket of saltwater without any plumbing attached, and the performance doesn't even compare to what I'm getting with my OTP 3000. So far this is a very expensive dud of a mod. I must be doing something wrong, b/c I've heard over an over again that the gen-x 4100 is supposed to rock. I'm going to also try and make my own venturi from 1" pvc to 3/4" back to 1" again, and insert a JG fitting at the 3/4" restriction just before it transitions back to 1", and then grind down the edges of the 3/4" plumbing so it transitions well.

As a side note, I bought the ER volute that has the venturi already attached to it. It looks like the venturi might have been put on wrong, b/c the air intake is located closer to the input of the venturi rather than the input to the volute, but it's already glued together. Not sure if this is right.

Anyway, I have a stock volute which is the same as the other one, and I'll try my own venturi to see what I can do.

Could my SCFH meter be off? B/c my numbers should be higher for my OTP-3000 as well. It just seems strange that I can't get more than 500 LPH of air out of a Gen-x 4100 with ER SP4. Any ideas?

 

[Skimmy]

you need to re-do the mesh mod...you must cut all the pins off of the plate, and i suggest you start out with 2 layers of mesh, and if you have it, a layer of gutter guard, gutter guard can go on top or bottom.
also, if you used zip ties, make sure they are perfectly alighned and balanced so it does not cause the impellar to wobble or be out of balance.
also, make sure you cut away all the mesh from the center washer where the 2 plastic washers meet, that must be clean and able to spin freely

if you have any issues, you can bring the pump to me at barrier and i'll do it for you

 

[DonW]

you need to re-do the mesh mod...you must cut all the pins off of the plate, and i suggest you start out with 2 layers of mesh, and if you have it, a layer of gutter guard, gutter guard can go on top or bottom.
also, if you used zip ties, make sure they are perfectly alighned and balanced so it does not cause the impellar to wobble or be out of balance.
also, make sure you cut away all the mesh from the center washer where the 2 plastic washers meet, that must be clean and able to spin freely

if you have any issues, you can bring the pump to me at barrier and i'll do it for you

What is the air to water ratio after this mod? What I mean is how many GPH are leaving the skimmer and how much air is going in. How does this compair to the stock (oem) numbers.

Don

 

[davidabrown66]

you need to re-do the mesh mod...you must cut all the pins off of the plate, and i suggest you start out with 2 layers of mesh, and if you have it, a layer of gutter guard, gutter guard can go on top or bottom.
also, if you used zip ties, make sure they are perfectly alighned and balanced so it does not cause the impellar to wobble or be out of balance.
also, make sure you cut away all the mesh from the center washer where the 2 plastic washers meet, that must be clean and able to spin freely

if you have any issues, you can bring the pump to me at barrier and i'll do it for you

Yah, I think I need some help here...I tried the zip ties, but I tried to zip them around the lip of the pinwheel after the pins were removed, and there wasn't enough room for the pw to spin. So, I ended up using fishing line.

I was thinking GG with my stock impeller or on the pw without the pins. I also think the ER venturi/volute is not that great...not worth the $ anyway. I'll mess with it this week, and bring it in this weekend if you're around. I'll try the GG on the bottom, and two layers of mesh. I did cut away the mesh from the center washer, but I think I only used one of the plastic washers if that matters.

What's your schedule like this weekend? Now that I looked at my schedule I see that Sat is gone. I can come by Friday around lunchtime or anytime on Sunday.

Thanks Mark!

 

[davidabrown66]

Thanks Mark for doing the mesh on my gen-x this past weekend. I'm still getting 30 SCFH without any plumbing attached so that's a big increase over what I was getting, and I'll be doing some more testing with other venturi's and adding the output plumbing to see if I can I increase the air to above 900LPH even after the plumbing is in place which is my goal for minimum LPH to make the switch from the OTP. Meanwhile, I'm also doing some work on the OTP-3000 to see if I can apply what you showed me with the mesh mod, to see if I can improve the #'s there as well. I'm really looking for 35-40 SCFH from the Gen-x before I switch over just to give me some room for headloss etc. once it's installed. I'd be happy with 32 SCFH from my OTP since it's already installed which would be roughly 900 LPH.

Anyway, I'm getting sidetracked again...just wanted to say thanks!

 

[davidabrown66]

Oh what a difference a day makes. Well, the Gen-x was doing relatively well at 30 SCFH until I opened it up and saw that it had a few strands of mesh that needed trimming b/c it was rubbing on the inside of the volute. I carefully cut those down to the same diameter as the rest of the edge, and voila...27 SCFH NOT good!! Then, I drilled out the restriction where the water leaves the pump...and now I'm at 20 SCFH!!! Word to the wise...don't do that!
I tried adding another layer of mesh on top of the two layers and GG, and still 20 SCFH. I think the plastic flap piece that allow water to exit the pump is more crucial than I thought. I also have the basic impeller as a spare, but not sure how to create a disk for that with the current tools I have.

Anyway, I have another Gen-x showing up on Monday with the NW this time instead of the PW. So, I should be able to use fishing line more easily or wireties if I want.

The other thing I noticed was the wattage. The pump runs about 90 watts when using the mesh and moving just water, and then when i lift the air tube out of the water so air can be injected it goes down to about 42 watts...which is below the rated 70 watts...interesting. Is that normal?

Does the Gen-x 4100 work better with 2 layers of mesh or 3? GG on top and bottom? Wireties better than 10 lb fishing line? I'm questioning it all again with this pump vs. my OTP-3000

 

[Skimmy]

after you drilled out the restricter on the pump outlet, it probably goes a different direction each time it starts up, you might want to restart the pump and try to get it to go the other direction, typically one direction is more powerful than the other.

also, have you seen this site than another member here made??
perfect for making the bottom disc, or modding a regular impellar pump

http://www.randystacye.com/diythreadwheel.htm

 

[Skimmy]

What is the air to water ratio after this mod? What I mean is how many GPH are leaving the skimmer and how much air is going in. How does this compair to the stock (oem) numbers.

Don

i think that would depend greatly on the individual pump used, as most have different sized intake/output, and impellar chamber size...
i dont know the air to water ratio on the skimmer pumps i modded, never tested, all i ever did was hook up a dweyer air meter to confirm increase in air lph. typically i see it double air injection, or come close to it.
i do know that with ati skimmers for every 3 parts of water the pump pulls in 2 parts air for an efficiency rating of approximately 67%. most other skimmers on the market have an efficiency of less than 35%

 

[DonW]

i think that would depend greatly on the individual pump used, as most have different sized intake/output, and impellar chamber size...
i dont know the air to water ratio on the skimmer pumps i modded, never tested, all i ever did was hook up a dweyer air meter to confirm increase in air lph. typically i see it double air injection, or come close to it.
i do know that with ati skimmers for every 3 parts of water the pump pulls in 2 parts air for an efficiency rating of approximately 67%. most other skimmers on the market have an efficiency of less than 35%

Ive seen the ati numbers, its on all the websites. Dont know why they would call it it a efficiency rating? I would call it a air to water ratio or something like that. What I wonder is if the mesh mod is pushing more than 13% air vs water into the skimmer at any given time. In other words if the skimmer while running held two gallons what percentage of that is air.

Don

 

[davidabrown66]

OK, enough is enough. I've given up on the Gen-x 4100 as a replacement for the OTP-3000. At best, the Gen-x produced 30 SCFH after SP4. This was with it just sitting in a sink with water so no output plumbing, etc.

Initially I wasn't able to get more than 22 SCFH, so I brought it into Barrier Reef and Skimmerwhisperer was able to put on a mesh that produced the 30 SCFH. I took that home and was looking it over to see why his produced better results. After opening up the pump to look at the impeller, I noticed a few strands of mesh rubbing on the volute edge so I trimmed those down to the same diameter as the rest and plugged it in. Now, it was at 27 SCFH. I had heard that drilling out the flap flange at the output of the Gen-x would yield better result, so I did that, and then my numbers dropped to about 20.

I tried several more times to get back what I'd lost, but the best I could do was 22 SCFH. I then ordered another Gen-x, and continued to try to get back up to 30 SCFH, but no...I guess I'm mesh impared when it comes to this pump. I also continued to apply what I'd learned to the OTP-3000, and I'm now getting 30-32 SCFH from it with less wattage used (78 watts). Drilling out the 1/16" edge around the volute, and more work on the output of the volute I believe dropped my wattage.

In a nutshell, I was really hoping the gen-x with ER PW, ER venturi and volute would've given me the 30+ SCFH without mesh, and then 35-40 SCFH after mesh, but the numbers were more like 18 SCFH and 30 SCFH respectively. IMHO, the OTP is still the clear winner here in my brief experience even though the impeller has a smaller diameter NW and whatever else has happened to the pump to make the 40+ SCFH unattainable.

Is there anyone out there able to get 35+ SCFH from a Gen-x 4100?

 

[mavgi]

you can get 40schf from gen x4100 i know that Kentrob in rc pull those # on his genx 4100.

 

[davidabrown66]

Thanks Mavgi, I just sent him a PM. I should probably reread the thread he started here:

http://reefcentral.com/forums/showthread.php?s=&threadid=966407&perpage=25&pagenumber=1

 

[Skimmy]

bring in the newer gen-x to me this weekend, i think i know what we can do
i have my new dremel and parts
and post what kentrob 's reply to you was too..

 

[davidabrown66]

bring in the newer gen-x to me this weekend, i think i know what we can do
i have my new dremel and parts
and post what kentrob 's reply to you was too..

I'll be there! Kentrob11 never replied to my PM, and I've gone over the thread he started that talked about the 40 SCFH on his Gen-x 4100, but he was using a bristle material (that didn't pan out) to get those numbers. I also looked over the design of the venturi and barbed adapter to duplicate what he did, and I didn't see any performance gain over the Euroreef volute/venturi.

My biggest problem for some reason has to be the mesh. You were able to get 30 SCFH when you did the mesh for me so I'm impaired some how, b/c I've done it 15 times since then, and I consistently can only get 22 SCFH even with a different nw impeller instead of the pw impeller from ER.

I probably won't see you until Sunday. I'll bring the old pw and the new nw and pump with some mesh and ties.

Thanks again Mark.

 

[davidabrown66]

Hey Mark, sorry I couldn't make it in this weekend, just too busy. Do you just work weekends? I'm out of town this weekend, but will stop by the following weekend. Really appreciate your help. I should be able to do some additional testing by then with some mods to the venturi that impur has done on his 4100 to see if that gets me back up to 900-1200 LPH.

 

[mungus]

Just wondering if you had any luck with getting that genx working.

Brian

 

[davidabrown66]

Just wondering if you had any luck with getting that genx working.

Brian

Got a chance to play around with it again two night ago, and I still must not be getting the mesh quite right. I've done the mesh 30-40 times on my OTP-3000 and I'm getting 900+ LPH from it, but for some reason after 20 or so tries with the Gen-x I still can't get the same numbers (30 SCFH) that Mark (Skimmerwhisperer) was able to get when he did the mesh on my Gen-x. My best is still 22 SCFH without any output plumbing attached. I still need to make it back to Barrier Reef to see if he can bless it again with his mighty powers

I've also tried different designs using just a ball valve with a 3/8" barbed fitting right where the ball valve exits just before the pump input, but that didn't help either.

Right now I'm using 2 layers of PF4 with one row of NW and wire ties. I've tried more layers of PF4 with and without GG, and then with and without fishing line. Mark was able to get 30 SCFH from 2 layers of PF4 with one layer of GG underneath the PF4, and then used wire ties. When I got it home after he did the mod, the numbers were the same, but there were some stray PF4 strands extending beyond the nw diameter and thought they might be hindering it from going beyond 30 SCFH so I removed just the ends so they only extended to the same diameter as the rest of the mesh, and for some reason I've never been able to get it back to 30.

I'm willing to ship this thing to anyone who has done the mod, and successfully gotten 35+ SCFH from it. I'll pay for postage to and from of course. If could see what I'm fundamentally doing incorrectly, I could make the final adjustments to my method of attaching mesh so I can finish the pump change over from the OTP-3000 to Gen-x. I have the plumbing pieces ready and waiting for the change over.