SCWD MODs: Modifying your SCWD to perform like a champ!

[JohnnyAirtime]

Ya know, I keep hearing how users who buy the SCWD don't like the limited flow. How it causes a bottleneck and doesn't allow very good flow from a high-pressure pump (capable of higher flow rates). Well, after I did some research on SCWDs, I'm now happily using three 3/4" SCWDs on my 240gal!
(I had always been using a 3/4" on my 125gal... but never knew it's full potential until this past week!)

I WANT TO SAY A HUGE THANKS to the folks who made a better mousetrap out of the SCWD. Open minded and Engineer oriented brains, came together and allowed me to renew my vigor in the SCWD product. Hence this post!! I'd NOT have found this information if it wasn't for a few fellow reefers... so, THANK YOU for that!!! ...I take NO credit in the MODs, and note they were NOT my idea. I'm just re-relaying the (old) information


First, I drilled out the inflow and outflow ports to 5/8"
... this in itself, made a huge difference!!

I then was able to repair a SCWD using knowledge I gained from another site. Cutting the top off, and removing the internal gear box. And then re-assembling it with the provided parts from HomeD.
(next time, I'll cut the lower half off - as seen in the following threads. I want to see if there's any advantages)

If you have been one to not use a SCWD due to the problems you hear about them, or the limited flow... fear no more!! Follow these links;)

(these links will provide you with ALL you need to know)
http://reefcentral.com/forums/showthread.php?t=843091
http://www.nano-reef.com/forums/index.php?showtopic=76847&st=0&p=697311&#entry697311
http://reefcentral.com/forums/showthread.php?t=845649

... I want to thank all of those who have done their homework!! It sure helped me restore faith in the SCWD!!!

PLEASE NOTE: This is for the 3/4" SCWD only. The 1" SCWD already has a removeable top and incredible flow rates. I am using 1200-1800gph pumps, and 3/4" plumbing. At one point in my 6 return lines, I had to go down in plumbing to a 1/2" adapter... the 3/4, and 1/2" plumbing, caused the 1" SCWD to NOT ALTERNATE!! You MUST plumb a 1" SCWD with 1" plumbing/fittings all the way to the tank!! Otherwise, there won't be enough out flow to spin the internal propeller. For this reason, I had to use 3/4" SCWDs on my tank as the 1" would not work correctly.

[BeanAnimal]

Any way you cut it (no pun) the devices rob a significant amount of flow in the way they use pressure to create mechanical motion and also are maintenance nightmares. The best way to mod a SCWD is to replace it with an Oceans Motions :D

[JohnnyAirtime]

Any way you cut it (no pun) the devices rob a significant amount of flow in the way they use pressure to create mechanical motion and also are maintenance nightmares. The best way to mod a SCWD is to replace it with an Oceans Motions :D

Maintenance nightmares? No, not really. There's nothing to maintain if the MODs are done correctly. And once the MODs are done, it's years of maintenance free operation.

Robbing significant amount of flow due to mechanical means? Hmmm, well... I've not done any scientific analysis, but the small impeller can be turned with a person simply blowing into the SCWD. That's not enough "resistance" to slow the current (IMHO). The bottleneck isn't in the mechanical operation, but more or less in the input/output ID sizes limiting flow. That's corrected when you DIY a PVC SCWD using OEM internals (for cheap!). So until you understand that it is NOT the pressure within the SCWD that drives the impeller, but the flow rushing past it... you should not spout inaccuracies.

Oceans Motions are an option, sure. But when I can buy a used SCWD for $25... and it cost me $4 to MOD... it's a no-brainer in comparison to an Oceans Motion at a starting price of $165 (new) or even used at $120 for one. I can buy (5) SCWDs for that price!. Also, your relying now on Electrical devices in a saltwater aquarium to power the unit. SCWDs are not reliant on your home electrical.

Thanks for the info! However, let's stick to topic.

[BeanAnimal]

Maintenance nightmares? No, not really. There's nothing to maintain if the MODs are done correctly.Sure they are :) The device relies on a moving impeller to create mechanical motion. Buildup of organic material creates friction that impedes the conversion. The very nature of the device dictates that it is high maintenance :)

Some of the mods have helped to facilitate the maintenance but organic buildup is still an issue as is the deterioration of the wear parts due to friction.

Robbing significant amount of flow due to mechanical means? Hmmm, well... I've not done any scientific analysis, but the small impeller can be turned with a person simply blowing into the SCWD. You mean a person blowing into a CLEAN SCWD that does not have water pressure acting against the motion of the mechanism :) Remember the action of the SCWD has to work against (divert) the water flowing through it.

So until you understand that it is NOT the pressure within the SCWD that drives the impeller, but the flow rushing past it... you should not spout inaccuracies. I am very aware of they way these devices work from both a pure mechanical standpoint as well as in relation to fluid dynamics. The "flow" through the device does not exist without pressure. Pressure and flow are intamatly related and can be described by Bernoulli's law... In any case, the very nature of the device dictates that it must take energy from the water to create the motion of the valve. The energy it takes from the water results in reduced pressure.

That is, it is important to understand that it takes energy to run the SCWD and the energy comes from the water being pushed through it. Any energy devoted to moving the gear is energy not devoted to water movement in the tank.

Don't get me wrong, I have no doubt that those who take the time to rebuild these devices can improve on their dismal performance to a great degree.

Also, your relying now on Electrical devices in a saltwater aquarium to power the unit. SCWDs are not reliant on your home electrical.Sure they are, they rely on the water flow from your electrical return pump :)

So to be clear, if it takes exactly 1W of electricity to turn the valve with an electric motor, it takes more than 1W of electricity to pump the water that turns the valve because you have to account for the frictional losses in the system ahead of the SCWD.

Lastly, my comments were not meant to take away from the success of your project and in fact were meant to be somewhat tongue in cheeck. I have have no doubt that your SCWD performs much better than it did from the factory and if it works for your purposes or others can benefit from the information you provided, then that is all that matters.

[imagex]

wonder if putting a 1" input on a 3/4" model would work cause i have a oceanrunner 6500 and it has a 1" output so i'm going to use that then output to 2 3/4" returns.. but have never seen anyone use a 1" input on the 3/4"model cause i know if i was to use the 1' model the scwd wouldnt work cause no enough flow... they're website is way off on they're gph assumptions.. unless it's asking for a higher pressure rated pump..

[JohnnyAirtime]

Sure they are :) The device relies on a moving impeller to create mechanical motion. Buildup of organic material creates friction that impedes the conversion. The very nature of the device dictates that it is high maintenance :)

Some of the mods have helped to facilitate the maintenance but organic buildup is still an issue as is the deterioration of the wear parts due to friction.

... and my 3/4" in 11months of use never had any buildup, or need to clean the unit. I'm not sure why it'd be considered a maintenance nightmare. I've had skimmers that were a maint. nightmare far beyond a SCWD device.

And everything wears out (electrical or mechanical). That's a no-brainer.

Lastly, my comments were not meant to take away from the success of your project and in fact were meant to be somewhat tongue in cheeck. I have have no doubt that your SCWD performs much better than it did from the factory and if it works for your purposes or others can benefit from the information you provided, then that is all that matters.

I hear ya, and didn't mean to sound so defensive (I re-read my reply). I simply am astounded at what I did... and why I waited to do it. I should have done it long ago!! Everyone I've met that has just sold me a 3/4"... had no idea they could be MOD'd. HENCE this POST!

... I won't even begin to debate pressure, volume, flow... I'm not smart enough! ;)

[JohnnyAirtime]

wonder if putting a 1" input on a 3/4" model would work cause i have a oceanrunner 6500 and it has a 1" output so i'm going to use that then output to 2 3/4" returns.. but have never seen anyone use a 1" input on the 3/4"model cause i know if i was to use the 1' model the scwd wouldnt work cause no enough flow... they're website is way off on they're gph assumptions.. unless it's asking for a higher pressure rated pump..

I don't know. I've seen the 3/4" fittings done often... and with good results.

BUT, I read the links I posted front to back... and one guy mentions the 3/4" SCWD won't work with too much pressure against the impeller. So maybe, your 1" supply could push that kind of "too much" pressure.

... and ya, that 1" needs Shamu Tank flow rates! (I've got one for sale! ;))

[BeanAnimal]

... and my 3/4" in 11months of use never had any buildup, or need to clean the unit. I'm not sure why it'd be considered a maintenance nightmare. I've had skimmers that were a maint. nightmare far beyond a SCWD device.

And everything wears out (electrical or mechanical). That's a no-brainer. The rate of fouling depends on many factors from feeding to alkalinity and calcium levels. As for wearing out, not all things wear out at the same rate :)

The steps you have taken will certainly make maintenance easier and help to prolong the life of the SCWD. It is a shame more thought was not put into the desgin to begin with.

[DeathWish302]

Oceans Motions are an option, sure. But when I can buy a used SCWD for $25... and it cost me $4 to MOD... it's a no-brainer in comparison to an Oceans Motion at a starting price of $165 (new) or even used at $120 for one. I can buy (5) SCWDs for that price!. Also, your relying now on Electrical devices in a saltwater aquarium to power the unit. SCWDs are not reliant on your home electrical.

Thanks for the info! However, let's stick to topic.

If you can DIY a SCWD, you can build a Swirlerstein.

http://www.reefcentral.com/forums/showthread.php?t=1483439&highlight=swirler+stein

I have had one in operation for around 3 years. Cost around $45 to build and I have cracked the case once to check for problems, but none to date. I might be using a little electricty, but I'll pay for the 20W of power used to NEVER have to touch it again (minus cleaning the PH).

How many PH's have you had that split open and caused a flood? Not saying a modded SCWD is not an option, but don't sell a DIY 'Seaswirl' short if you haven't tried one.

[JohnnyAirtime]

If you can DIY a SCWD, you can build a Swirlerstein.

http://www.reefcentral.com/forums/showthread.php?t=1483439&highlight=swirler+stein

I have had one in operation for around 3 years. Cost around $45 to build and I have cracked the case once to check for problems, but none to date. I might be using a little electricty, but I'll pay for the 20W of power used to NEVER have to touch it again (minus cleaning the PH).

How many PH's have you had that split open and caused a flood? Not saying a modded SCWD is not an option, but don't sell a DIY 'Seaswirl' short if you haven't tried one.

(what happened to staying on topic for SCWDs?!)

Either way... it's a neat option if your into powerheads. (however, I am not)

I myself am using my 3 return pumps as supplies for my 6 returns via loc-line. This is why a SCWD is such a neat item to use. It's allowing me to keep the powerheads out of my tank, use 1 pump per 2 returns, and still have plenty of water movement. If I had simply split the returns via a Y barb fitting, the return pump doesn't have enough pressure to provide ample water movement to two constant return lines (not for my liking anyway). Plus I don't get any surge using it that way. Since the SCWD will only allow one output at a time (more or less), it keeps very close to the original pressure from the return pump. Providing great surge or agitation in the water!

Add to it: I don't have a cord, or a device in my display. SO MUCH CLEANER when you don't have things hanging in the tank or visible to the onlooker.

Again, this thread was to remind SCWD users what the possibilities are for their SCWD. Everyone knows there's other options to using a SCWD device... but, when you think your SCWD is so restricting... you need to MOD it and realize it's full potential.

[DeathWish302]

(what happened to staying on topic for SCWDs?!)

Sorry boss, I read Ocean Motion and heard Sea Swirl from the voices in my head.

Sorry for 90deg screeching turn to the right.....:headwally:

No harm intended.

[jeff@zina.com]

The best way to mod a SCWD is to replace it with an Oceans Motions :D
Gotta agree here. Of course, the price is out of SCWD range... :)

Jeff

[txmike2]

I will post pic later I cutt up a SCWD and machined a new body for it and made it in to a 4 way .It has been up and running for 1.5 years never had to take it appart to clean .Pushing it with a Mag 24 .It took some time to get the drum the way i wanted it to flow .It has worked great all being said my next one will be a highbred of the OM but will runn it with a stepper motor off my PLC controller .

[NanoReefWanabe]

I will post pic later I cutt up a SCWD and machined a new body for it and made it in to a 4 way .It has been up and running for 1.5 years never had to take it appart to clean .Pushing it with a Mag 24 .It took some time to get the drum the way i wanted it to flow .It has worked great all being said my next one will be a highbred of the OM but will runn it with a stepper motor off my PLC controller .

now this i wanna see...

[txmike2]

hear it is

http://i736.photobucket.com/albums/xx7/txmike2/DSC07378.jpg

http://i736.photobucket.com/albums/xx7/txmike2/DSC06325.jpg