SCWD Modifications. If you only knew!

[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!

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)

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/inde...1&#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.

[ajn81]

Great info, thanks! What reasons do you have for now wanting to cut the bottom off rather than the top? Looks like the first link you posted is top cut off, second is bottom, and third is a complete rework. Would you employ methods from all three mods? Or is one of these mods better than the rest?

[JohnnyAirtime]

Great info, thanks! What reasons do you have for now wanting to cut the bottom off rather than the top? Looks like the first link you posted is top cut off, second is bottom, and third is a complete rework. Would you employ methods from all three mods? Or is one of these mods better than the rest?

Thoughts on why to use top, or bottom cut-a-way;
The top removal is easy, but the way the top "cleanout" fitting is attached is somewhat scary. A "butt joint" if you will. I have one done in this fashion right now, and it's hard to let go and think the solvent bond will hold for years to come. Imagine it blowing off? OMG! ... I'd have 1200gph flowing until my 80gal sump was empty. Yet, it is a similar material bonding together and you can use ABS glue.

The lower cut away and addition of the PVC fitting... is a bit more "bond" of materials (more surface area). You can 'fit' the PVC into the SCWD housing if your crafty and want more material to bond together. Plus, it makes a nice fitting for connecting a 3/4" hose barb too. But the lower cut-a-way makes it harder to see your SCWD action when testing the turn of the gate.

... it's a toss up when I get right down to it. Tough call.

Either way you slice it or dice it... it's a great way to access the internals and either fix something broken, or clean them out of debris. They are so simple inside, yet so effective when they work good. And now, that mine are drilled out... WoW... what a difference! It's amazing at how much better they work, and the pressure spraying from my loc-line in comparison to 'not drilled'.

I'm picking up two spare SCWDs tonight, to modify and keep on hand. I'm now a firm believer in them and how well they work. Before, I was bummed at the output and how it turned a high pressure pump into a drizzle. No More!!