Meshing the needlewheel impeller

[Marc]

I'm still too scared to destroy a $100 impeller for my Euro-Reef 12-2 quite yet. Even for registered owners, that's $75 each, and I have TWO! So I grabbed my back up ASM G-3 since it uses a Sedra 5000 pump as well. It's been acting up, and I wanted to know what the problem was. After opening it up, I found the ceramic shaft was broken and the magnet has a huge bulge on one side. That can't be good.

So I dipped into my backup bin of goodies and pulled out another Euro-Reef impeller and ceramic shaft, and got to work. Here's the impeller and the mesh.



I cut out a few squares of the material for the layers.



I cut off the pins with a utility knife, leaving two nubs at 12 and 6 o'oclock. It may not make a difference, but I thought it might help keep the mesh in place when it starts up (against the torque). Next I trimmed off the edges, leaving some excess but had to trim it again so it wouldn't drag against the inside of the impeller housing.





Then I tested it. I grabbed a bucket, 2g of warm tap water, 2 cups of salt, and a modded pump.



There was a faint Niagra Falls like mist emitting from the from the bucket.

Good enough for me. I put it in my LR-cooking barrel, which has had the same 20g of water for the past month. It has a single pump, salinity at 1.025sg and about 55g of LR that is shedding any remaining detritus / algae.

One minute:

[Marc]

Again at 3 minutes.


And at 15 minutes.


I'm now waiting to see what occurs...

I didn't test for wattage before, but my other Sedra 5000 uses 40w of power. I don't have a air meter yet.

[Marc]

Currently the pump is pulling 59w of power. The bubbles are rising further up the neck.

Here it is at 1 hr 20 minutes:


And at 1 hr 45 minutes:


This is what is being skimmed:

Marc,
Nice work. Did you ever get an Airflow meter to see what it's pulling ?
Also, can this mod be used on smaller non-needle wheel pumps (eg a CA 1800) ?

[Marc]

You'll need to check in on that long thread on RC. I think that is one of the pumps that has been discussed.

I don't have an airflow meter. If anyone in the club does, I'd like to borrow it.

[Marc]

I got tired of waiting for something to happen. Since the LR has been cooking for so many months, I have to assume the water is just about as clean as it'll get.

I took about a half cup of skimmate from my reef's skimmer and poured it into the ASM. It took about a minute to collect it all back out.




The bottom line to me is that the modification works, and I see far more airbubbles in the body of the skimmer. In the past, it just didn't seem to have nearly enough air in the reaction chamber.

Are you hearing any noise from it? I know Tony said he was going to have to try and balance his better because it was making a lot of noise.

Marc, I did the same thing on my sedra 9000 this weekend. It's pulling more air (although I have no air meter), but it's much louder. I had to lower the water level by 2-3 inches in my asm g4x. I am planning on pulling the venturi out and opening it up a little more so that I can get more air to the skimmer.

[TriggaFish99]

Looks good Marc!

I did something similar to an Ehiem pump on my skimmer. I used gutter guard instead of the mesh.

What exactly is the mesh stuff and where did you get it? I'm not sure I'll pull my pump apart right now to try it...but I may the next time I have to clean it.

PM Mavgi on RC he may still have some of the mesh left ,
$2.50 for a large envelope of the mesh, hopefully I will get mine in the mail today
http://www.reefcentral.com/forums/showt ... did=966407

[Marc]

I switched out one impellar in my Euro-Reef 12-2, and was able to twist open the gate valve at least four or five twists (not 360 degree turns though).

There's no doubt more air is in the skimmer body now.

I never realized there was a difference between the ASM and the ER Sedra pumps. I was kind of hoping I could just swap the pumps out but the connections aren't even close to the same. While swapping out impellars, I cut away some of the mesh in the center so it wouldn't rub on the ceramic shaft. It didn't want to start right up, but it is an older impellar. By opening up the cover plate slightly, the pump started spinning as it should and I'm getting some thick skimmate pouring down the outer side of the collection cup's neck.

[Marc]

Update: After about a month of use, one impellar had to be repaired with new mesh.

Here is 4 days of skimmate. I feed once a day, and don't dose phyto.

That's really a Major difference Mark, you sure you're not willing to buy a spare impeller ?

[Marc]

I did buy a backup for the ASM skimmer so if I have to use it, I got it.

[GraviT]

I just did the mesh mod to the Sedra 9000 on my ASM G4+ and I can certainly tell a difference in bubble size! Only problem is the hum of the pump seems a good bit louder. Does this go away with time, or do I have a balance issue perhaps? The mesh is held on with small wire ties, buckles facing the front of the impeller.

For mesh, I used a piece of Enkamat 7010 and a piece of 7220. The 7220 is about as thick as 2 pieces of the 7010 and has a flat bottom which rests nicely against the disk.

For those wondering, I got my Enkamat free by doing a google search for the product and and ordering a sample from a retailer's website. Unfortunately, they send a card with 6 different 2"x2" squares, so I had to combine 2 different types, only 3 of which seem to be suitable for this purpose. One word of warning, if you order the samples from them DO NOT use the 7910....it has a biodegradable mesh woven into the Enkamat. I'm not sure what it is, but I wouldn't take the chance.

I am waiting on some larger samples from the manufacturer, so hopefully, I'll have some backup mesh if this configuration fails.

Kevin-

Although mesh modding your impeller can produce finer bubbles and increase efficiency, the downside is that it makes the pump run a little louder. I noticed the same thing on my Sedra 9000.

[Marc]

Yes, I think it makes it louder as well, although sometimes it can be solved by readjusting how the pump is hanging off the body of the skimmer. It seems like the sound resonates or transfers to the body if the pump is leaning on the skimmer itself.

[GraviT]

I am VERY impressed with the performance of my G4+ after the mesh mod. I've been running it very wet on purpose, but even so, the stuff it's pulled in 3 days is just nasty! I alternate Nori one day, then meaty food the next and don't dose phyto. Excuse the fact that it's leaning to the right a bit..I need to re-do my drains so it fits better in the sump.

[TriggaFish99]

Marc,

Did you do the mesh wheel to both pumps? I read this and I can't tell for sure.

Also, how's the mesh holding up.

I'm thinking of doing this to my CS 12-1, but wanted an update from you first.