The Ultimate Octopus Skimmer!

[BobC63]

I thought this project was cool enough - and turned out well enough - that it deserved it's own thread:

THE ULTIMATE OCTOPUS SKIMMER MOD - 2 SKIMMERS, 1 PUMP

The skimmer I chose to mod was a Reef Octopus NW200. It is an 8" diameter skimmer, 24" tall with a single pump called the OTP 3000... it is a good, basic skimmer design; nothing fancy, no bubble plates or recirc pumps or cone body... just a decent skimmer that has been around a few years, is plentiful and relatively inexpensive. Here I am going to turn it from a good performer into a skimming monster!!!


First thing we are going to do is "unchoke" the OTP 3000 pump... this is actually a very powerful pump; it is basically an Oceanrunner 3500 with a NW impeller... 100% stock (in NW form) it is rated at 750 gph and 15 scfh of air. Here we are going to mod it to reduce the water to around 450 gph and up the air way, way up to approx. 50-54 scfh!

Step 1) remove the stock inlet pipe w/ the stock 1/2"venturi reducer and 1/4" I.D. airline - utterly useless!

Step 2) remove your inlet cover and the stock NW impeller and do a meshmod w/ 3 layers of PF4 Enkamat...

Step 3) place the impeller back in, reattach the inlet cover, and drill a 1/2" hole in the inlet as close to the inlet cover as possible. Insert 1/2" vinyl tubing airline into the new venturi hole. Make sure you cut a "vee" in the airline and face the opening in the "vee" towards the inside of the pump. Add a drop or 2 of Crazy glue to keep it in place:

Step 4) I attached the custom elbow I fabricated to the pump... I made it out of a PVC 3/4" 90 degree "Y", glued on the metric fitting from the pump output on the single end and 2 of the NW200 retaining rings on the "Y" end. I also put in a couple of 3/4" O-rings and drilled (4) 3/32" holes near the "Y" ends, then screwed in tiny #4 sized nylon screws to hold the retaining rings in place... sounds complicated, but once I figured out the design it took maybe 10 minutes to assemble it - and the whole elbow fitting cost less than 5 bucks to make:

Step 5) I hook up one skimmer body, like so:

Step 6) attach the 2ND SKIMMER BODY to the other opening, like so:

The finished project... I called this ultimate skimmer mod "THE TWIN TOWERS":

Of course, the big question is...


DOES IT WORK????







HELL YEAH, IT WORKS!!!

Already starting to get some good foam heads only 15 minutes after the start-up:

I'll put up some "after break-in" pics a little later...

 

[returnofsid]

Bob, welcome to Reef Frontiers!! Great mod thread!!!

 

[BobC63]

I actually finished this mod a couple of weeks ago... here are some pics taken recently to show how it is skimming:

These were taken around 24 hrs after emptying the collection cups; so, this is around the daily production of skimmate - 2.5 to 3 cups of nasty smelling, dark greenish-brown nog

The first couple of days I had to adjust the standpipes quite often to even out the flow between the 2 skimmers and find each one's "sweet spot"... but I haven't had to make any further adjustments since:

Here's a shot of how the whole setup looks in my DIY Rubbermaid sump /fuge setup under my 225g Reef:

BTW, how do you like my DIY sump?

(Guess that's a whole other thread :lol

 

[ajnweb]

Nice mod!

And DIY sumps usually seem to be the best anyway, looks good, and if it works why pay more money for a prefab unit!

 

[Dr. Dee]

Wow that's so cool

 

[as1720]

now post picture of the rest of your set up! I like what i see so far.....I really want tot see your stand!

Thinking of doing the whole rubbermaid sump myself, think i will double the rubbermaids though (one inside the other) just in case i have heard some horrier storiers about rubbermaids!

 

[senna]

that a sicce impeller not otp3000

 

[BobC63]

that a sicce impeller not otp3000

yeah, I forgot to snap a shot of the meshmod before I put the volute cover back on so I just "borrowed" a pic of a typical meshmodded impeller - but it's pretty much the same idea...

 

[Skimmy]

nice, considering 45-50 scfh is waaay too much air for the neck of one of these skimmers, they seem to max out at around 35 scfh.


although if it was me, i'd put a meshed pump on each skimmer body for the max of 35scfh x2...

also, i'd try to find one of the new otp 3000 pumps with the larger outlet, that is the main thing holding back the power of that pump.

 

[luke33]

Looks good bob. This is definately the first time i've ever seen something like this done. What kind of wattage is the pump running at with all that head?

Couple pics

 

[Saltyfish]

nice, considering 45-50 scfh is waaay too much air for the neck of one of these skimmers, they seem to max out at around 35 scfh.


although if it was me, i'd put a meshed pump on each skimmer body for the max of 35scfh x2...

also, i'd try to find one of the new otp 3000 pumps with the larger outlet, that is the main thing holding back the power of that pump.

How do you know the neck can only handle 35 scfh, also if the 50 to 54 is split between two skimmer bodies wouldn't the scfh be split between the two bodies?

 

[returnofsid]

LOL Because he's the "skimerwhisperer" Duh.

 

[BobC63]

How do you know the neck can only handle 35 scfh, also if the 50 to 54 is split between two skimmer bodies wouldn't the scfh be split between the two bodies?

This whole project came as an offshoot of a long thread Luke33 started back in 2007 (I think) on a different site titled "NW200 Step by Step to 40 scfh".

Luke33 went through a series of mods designed to get the skimmer up to 40. It ended up that once you got over 35 scfh the turbulence and gross amount of air overwhelmed the neck and skimmer performance actually decreased after 35. That statement came about as various other modders (besides Luke33) reported the same results with excessive turbulence / diminished performance above 35 scfh.

I came in to the thread around this time and with a different take on a few of the mods I managed to get to 42 scfh steady with a 'manageable' amount of turbulence. More than some would like, but the skimmer performance was stable. Anyway, I felt the pump itself still had more to give but the skimmer couldn't handle any more air. So I posted that maybe we could redo the neck (larger diameter) or perhaps someone should try running 2 skimmers off of one 'supermodified' pump.

Well, about that time a couple of self-proclaimed "skimmer experts" over at this other site jumped the thread and proclaimed the idea of '2 skimmers, 1 pump' as "impossible" and quoted the usual 'invisible sources' and psuedo-scientific equations to declare that it couldn't be done.

Well I am never one to resist a challenge. So I got to work on it - and here we are

And yes, a 54 scfh pump going through 2 bodies would net approx. 27 scfh per body... not the ultimate air number per body, but combined it is the highest anyone has gotten out of this pump (that I am aware of, anyway) and having 2 bodies means twice the water capacity, dwell time, etc. vs. a single bodied unit...

And, heck, it just looks cool...

 

[BobC63]

Looks good bob. This is definately the first time i've ever seen something like this done. What kind of wattage is the pump running at with all that head?

Hey Luke -

Believe it or not, when I checked it an hour or so after intiial start up, the Kill-A-Watt read 54w... only 2w more than the last time that I checked it on a single body, and still less than stock (65w)

My guess is that with the 1/2" airline and so much air getting in that the impeller drag is reduced so much that the extra head pressure of 2 bodies isn't enough to push the wattage too high.

I will also say that stock it is supposed to pump almost 750 gph and my guess now is that we are down around 425 - 450 gph total out of the 2 bodies. When I ran it on a single body it looked more like 600 gph or so of water with 42 scfh of air. So, as the air goes up the water goes down... which makes sense.

 

[trido]

You definately have the coolness department cornered.
Great job on doing your homework to get the most of of your mod.

 

[luke33]

Yep, i agree with you. Thats a great wattage too. Nice job on that. With those two bodies i'm betting your good for 250-300g. I've hooked up a sicce on an octo as a recirc and was getting 37scfh as a recirc. It was right at the edge of to much. Perfomed increddible though : ) Good stuff man, good stuff.

 

[amashun]

i did mod mine with 8mm air connector and found it works not bad. but it is good to see something even better!

seriously, i though mine was doing pretty alright from a 38W pump

your one even better! thanks for sharing. i want to try that out too.

 

[Saltyfish]

I love things that just look cool, that is why Matt did a dual stack for me, it just looked cool.

Of course there were other reasons but I think Matt just wanted to make it look cool and he did an amazing job!

 

[BobC63]

I love things that just look cool, that is why Matt did a dual stack for me, it just looked cool.

Of course there were other reasons but I think Matt just wanted to make it look cool and he did an amazing job!

In this hobby "coolness" is half the attraction -

Awesome double Beckett BTW

 

[Skimmy]

Im curious, is 54 scfh @ 54watts what the pump is pulling while connected to the 2 skimmer bodies?

also, there are a couple versions of the "old style" otp 3000, do you know if yours is one of the older more powerful version, or the newer , less powerful version... then theres the "new" version with the larger pump outlet and the newer venturi...considering it's cost, it might be cool to mesh and try on your skimmer(s).