Aquarium Advice - Aquarium Forum Community

Aquarium Advice - Aquarium Forum Community (
-   Saltwater Reef Aquaria (
-   -   OK..what's a SCWD? (

Brad 11-05-2004 06:58 PM

OK..what's a SCWD?

RogerMcAllen 11-05-2004 07:02 PM

I'm not sure exaclty what it is, but it is something you put at the end of your PH which periodically changes the waterflow to create turbulence.

captivereefs 11-05-2004 07:07 PM

checkout watch the video and you will see exactly what it is!

mrcowboy 11-05-2004 08:03 PM

No worries guys I asked myself that same question. A SCWD is known also as a SQUID. Its a type of plumbing that kinda works like a wave maker. Its pretty much hooked up to your pump. The water is spit from the pump into hosing. It travels half the distance to ur tank and enter the SCWD. The SCWD has 2 other hoses connected to it leading to two seperate flanges (drainage into your tank). The benifit of this is that both of ur flanges are not fed water at the same time. Pressure builds up in the chamber causing it to switch from one flange to the other. In my set up it switches every 22 seconds. So one sec its putting water on one end of the tank and 22 sec later it goes to the other end. It pretty much helps out circulation in ur tank.

Its a cheap way to have a wave maker.
No electricity is involved.
If your satisfied with its circulation like I am you don't need a power head in the main tank.

A little extra plumming at start (but its easy)
Due to gravity you lose some gph so you may need to upgrade or get a stronger pump.
You'll open the box and see the thing and say "I paid 30-40 bucks for this thing?" but its well worth it! GL

indy 11-06-2004 06:34 AM

Yep, it looks cheap. But you don't really feel ripped off until you pick it up. Feels waaaay cheap. But it works good. :D

fishfreek 11-06-2004 09:22 AM

Its built fine. Its a plastic exterior and im not sure how the inside it built but baistly ther is an impeller that rotates with water current and moves to close off one side and then alternates to close of the other side while opening the previously closed side.

Here are a few photos of my SCWD manafold before instaling it. As you can see you have teh supply comming from the bottom and then the two returns going out from either side. You have to use tubing to connect the SCWD to the plumbing but I then converted it to PVC for ease of plumbing after that. I used 3/4" tubing and plumbing.

revhtree 11-06-2004 10:21 AM

Do you guys use this set up for the return from your sump?

quarryshark 11-06-2004 10:32 AM

I have one on my tank and it works like a charm.
Rev, you use it on your return pump. Single hose from the pump, the SCWD splits it in 2 like in FF picture. I have one return in each corner of the tanks pointing to the middle. In my setup it is really nice, all the plumbing is incorporated within my overflows. Can't see the plumbing at all. Strong flow too.

fishfreek 11-06-2004 10:43 AM

Yes I do use it that way. You can also use it in a closed loop fashon.

revhtree 11-06-2004 10:44 AM

What if you loose power? What about loosing your water on the floor?

fishfreek 11-06-2004 10:46 AM

Having the SCWD in the system doesnt change anything in that respect. Its just an easy way to have water be divereted automaticly between to outlets.

You still need syphon breaks on the return lines and you still need to run your sump low enough that it can hold any backflow when a pump is powered down.

revhtree 11-06-2004 10:52 AM

Ok, I got it. You can drill a hole in both the PVC returns just above the water level right?

fishfreek 11-06-2004 10:55 AM


Now just to make sure everyone is following along. You are not going to drill a hole in the SCWD! You would drill small holes just above/below the water line on the acutal PVC returns that are inside the tank that is attached to the SCWD. In my photos for example I have small 1/8" holes drilled in the short 3/4" stright section of PVC that is connected to the final 90* elbow that acutal outputs the water.

revhtree 11-06-2004 11:00 AM

I dont know why I was having such a problem with that! :roll:

Thanks All!

quarryshark 11-06-2004 11:04 AM


You are not going to drill a hole in the SCWD
LOL, that would be messy. :lol:

revhtree 11-06-2004 11:07 AM

A little off topic, but how far under the main water level do you guys have your return water coming in? :D

quarryshark 11-06-2004 11:51 AM

I have built in overflows, so in my system its kinda set. About 3" under the surface.

Brad 11-06-2004 08:23 PM

That is really cool. I'm very glad I asked what that was. I could use this. My only problem is using flex tubing connections makes for a lot of silly plumbing work as I'll have to modify my 1/2" PVC return.

I've never seen them for sale. Who is supplying these?

fishfreek 11-06-2004 08:28 PM


I've never seen them for sale. Who is supplying these?
Just about any online retiler will have them. I would of course suggest checking our sponsors first. :wink:

It wont be hard modifying the 1/2" return. Just get a 1/2 - 3/4" pvc adaptor and then a 3/4" pvc - barbed hose connector. Then slip on your tubing and into the scwd. Use some nice hose clams to secure the tubing. Then do the reverse for the two returns. I would use 3/4" though for the returns vs sizing back to 1/2".

Brad 11-06-2004 08:53 PM

I'll consider changing to 3/4"

Does the SQWD have to be mounted vertically, like your photo?...or will it work if mounted horizontally?

quarryshark 11-07-2004 12:23 AM

I have mine horizontally mounted, works fine.

fishfreek 11-07-2004 09:51 AM

I dotn think orentation has much to do with it unless the mechanicals inside require gravity to be comming from a specific direction. The internals are somewhat secret but they operate on the water flowing thru it so I suspect there is an impeller in there and some gears so gravity wouldnt be a factor much.

All times are GMT -4. The time now is 09:58 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.