Modded sedra 5000 (ASM) venturi

[trido]

With all the talk of thread wheel mods I started looking at my skimmer. I have never been satisfied. I have an ASM G-3 rated for 180 gallons on a 165G system. No wonder huh?
I decided to start with the venturi. My Sedra has a venturi with 1" PVC which reduces to an opening of 9/16" in the middle. It has a venturi molded into the reducer with an air inlet of approximately 9/64". A 3/8" flex line hooks to the venturi opening. I started by drilling the venturi opening larger but was not pleased with the results.
I then cut the venturi off and drilled a 3/8" hole for some hard pipe I had laying around . I sanded a 45 degree angle on the line and it fit snugly so I tried it. I definately had more air intake but had significant loss of water movement depending on how I adjusted the air pipe into the reducer. I used the skimmer like this for three days(and adjusted the flow ratios) and liked the results but wanted better. The air intake went from 9/64" to more than 1/4" so I doubled air capacity. I felt like the water intake was my next hurdle for more performance.

 

[trido]

I have an abundance of PVC parts lying around so I grabbed a 1" coupler. It is about 1/32" smaller than the sedra venturi so I used it. I drilled the 3/8" hole. I knew I would have to reduce the water flow through the 1" coupler so I cut a steeper angle on the 3/8 hard pipe so the air would come out of the middle and shoved it all the way to the bottom. I used it for a day and felt it needed less water flow to allow more hang time with the air bubbles. To do this I just cut a piece of pipe and put it in front of the venturi.
I am really surprized at how much this simple mod has doubled the perfomance of my skimmer. I doubt that I will mod my impeller now. The only down side of this mod is that the venturi is REALLY LOUD. I have fixed that by using a 2' long 1/2" hose with the end in a kitchen towel. With a drill bit and sander anyone can do this for less than five dollars.

 

[trido]

Just thought Id post that I cleaned my collection cup before posting this. After and hour and a half it has 3/16" of skimmate. A little light, but never the less.

 

[ChrisRD]

I think a lot of stock designs can benefit from minor mods like this. Good work. 8)

 

[trido]

Here is a pic of the new noise reducer I built. Just a 3/4" end cap glued to a coupler. A 1" end cap slipped over the coupler and 3/8" holes drilled for air flow adjustment.

 

[bleedingthought]

First of, thanks for the PM, trido! 8)

Couple of questions: Did you glue any of these pieces together or they just fit snugly? And just to make sure, the hole on the tubing faces the skimmer, right? And the noise reducer works better than the towel ( )?

 

[Anonymous]

interesting and glad it worked.

Just curious because Mr. bernouli is telling me that to suck the maximum air, the hole should be at the fastest water flow and parallel to the water flow. I wondered if you had considered or tested just putting the tube into the center with a straight cut instead of the 45 degree angle? But then perhaps the turbulence of the 45 degree angle helps make finer bubbles.

my .02

 

[trido]

First of, thanks for the PM, trido! 8)

Couple of questions: Did you glue any of these pieces together or they just fit snugly? And just to make sure, the hole on the tubing faces the skimmer, right? And the noise reducer works better than the towel ( )?

Wow! very interesting that the post above has two of each pic.. I can assure you that I didnt post two.
The pieces for the venturi fit snuggly. The hole in the tube does face the impeller and the noise reducer works only as well as the towel but is much more compact, and looks better to. Also, I put filter floss inside of the noise reducer. I dont know if it is helping or not.


Beaslbob wrote:

to suck the maximum air, the hole should be at the fastest water flow and parallel to the water flow. I wondered if you had considered or tested just putting the tube into the center with a straight cut instead of the 45 degree angle



I have not considered this. I will try it now with reservations though. I think that I will get increased water flow and and thus reduce efficiency. As with alot of mods. There is going to have to be compromise with some aspect of perfect engineering.


EDIT:
After changing the venturi back and forth between the two designs and adjusting the "new" design. I have come to the conclusion that this ten minute venturi cant get much better in air flow. I will stick with the original one I posted. I will now make the decision to either mod the impeller to a thread wheel of just make the skimmer recirculating

 

[Anonymous]

thanks for trying.

Perhaps I will try your design on a power head venturi I use to suck air from a hob overflow.

Or perhaps both designs are efficient enough. Sometimes you can do 3 times the work just to get a few % change.

thanks.

.02

 

[bleedingthought]

Wow! very interesting that the post above has two of each pic.. I can assure you that I didnt post two.

Your picture act like your posts sometimes! :lol: :wink:

Thank you for the answers. One more question: Did you get that 3/8" rigid tubing at HD also?

 

[trido]

The rigid airline came from Tap plastics. It was left over from other DIY projects

 

[Anonymous]

I just got the same effect by adding a 3 watt air pump to pump air into the venturi.

 

[trido]

I just got the same effect by adding a 3 watt air pump to pump air into the venturi.

Sweet deal.

Id bet that they both cost the same now but in the long run my mod is probably more energy efficient. Your mod is definately good for those without tools though. You know me. I love to build things.

 

[bleedingthought]

Duane, I still have to mod my skimmer. Things have gotten entirely too crazy the past two weeks, though. After this weekend, things should be a lot calmer and I'll have the time/money. I'm still waiting for a response for my last PM, though. :wink:

 

[Anonymous]

I have a sedra 3500 on an ASM G2. I'm going to attempt to modify it. Maybe this afternoon. I need a project.

I also need to mod my intake. It's way to high and is wetting my bulbs.

 

[RandyStacyE]

I use a GenX-2400 on my skimmer. I found that the stock venturi sucked so here's what I did:

1 - Chucked the GenX venturi (very important)
2 - Picked up a barbed fitting ($00.50)

3 - Chopped off the end and drilled a hole for 1/4" ID air line

4 - Attached it to the volute ~ done.

I did not shove in the hose or cut it at an angle.

I wonder if the dimensions of the ASM venturi is the same as the venturis Euro-Reef uses.

Here's the dimesnions of the GenX venturi. Notice that the interior is bigger than the ASM measurements (9/16")

 

[bleedingthought]

So, are you going to glue the hose into the hole?

Looks good! 8)

 

[bleedingthought]

P.S. 'Sucking' is good when it comes to venturis!!! That's what they're made to do!!!

 

[RandyStacyE]

It's not necessary if you don't move the hose much. I don't like to glue things unless I have to.

 

[midlands98]

Hey! Please help if you can. I managed to break my venturi for an asm g.4 skimmer. I cannot get all seas marine or champion lighting to help me. I don't want to get stuck with a 400 skimmer that the manufactureer and wholesaler won't support. Can anyone help me? Gary in Atlanta 404 451 9836
Many thanks for any assistance.