View Full Version : ReefDevil III, right angle after output?

01/24/2000, 07:34 PM
First off, I'd like to thank everyone on this list and that other
unmentionable bboard for all their great information. I've been a lurker
on this bboard since it's inception and a lurker "over there" for over
a year. All that info helped me setup and run a 5 gallon nano reef for
a year and now the 75 gallon mini reef is up and running.

It's time to join in the discourse now though, 'cause I can't seem
to get my ReefDevil III skimmer working properly.

Space is tight under the tank, but I wanted to keep the skimmer outside
the sump for easy access and cleaning. The only way it fit was to put
a street-ell (right angle bend for tight spaces) on the output of the
skimmer, then fit that to a bulkhead in the sump, with a gate valve
inside the sump. That way the skimmer could sit parallel to the sump
and just barely fit inside the stand.

After 4 weeks of fiddling, the skimmer still isn't producing dry foam
with any reliablility, and the driving pump (Rio 3100) has to be
throttled down to less than 1/3 (gate valve between pump and skimmer)
to keep it from overflowing with wet foam.

Would a right angle on the output of a ReefDevil produce enough back
pressure to keep it from producing dry foam? The output of the
skimmer is above the water level in the sump to avoid that
backpressure problem, but it didn't occur to me at the time that the
right angle itself would be a problem.

Any thoughts? Does anyone else have a setup like this?

I'll probably cap off the bulkhead and put the skimmer inside the
sump, but it'd be great if someone could confirm this theory before
a pain-in-the-butt sump reconstruction.


Steve Richardson
01/24/2000, 07:48 PM
Dirk -

I have the RDII, but I think its probably quite similar.

Its very sensitive to backpressure. (Remember in the directions where it says a 1/4 turn on the gate valve can make a big difference?) What I would say is - if your 90' is COMPLETELY above waterline in your sump, you should be O.K. If the 90' is partially or completely submerged, it may indeed create enough backpressure to cause a wet foam.

Did you add enough bio-balls to the collumn? A couple more can help you make a drier foam too.



01/24/2000, 08:36 PM
Thanks Steve,

The 90' is completely above the water line, maybe 1/2 inch between
the bottom of the 90' and the top of the water in the sump. I added all
of the bio-balls shipped to the downdraft tube, 25 in total if memory
serves. I'd heard that the more bio-balls, the drier the foam. Can you
have too many bio-balls though? Maybe not. Other posts have mentioned
20-23 bioballs in the downdraft tube.

A 90' bend is supposed to add 1 foot of head in back pressure to a
circulation pump. Is that the same as saying that one 90' bend in the
output of the skimmer is equivalent to having the output of the skimmer
travel upwards for one foot, or having the output of the skimmer be
one foot underwater in the sump? Nah, that can't be or riser tube
would be completely filled with water. Hmmm. . .

I think the difference between the RDII and RDIII is the RDIII has a
larger base with a higher output, to help in the war against

Thanks again-

01/24/2000, 08:42 PM

I've got an RD3 and had the same problem for quite a while. Mine is in the sump but the water line is just at the bottom of the output gate valve. After doing a ton of fiddling and adjusting someone here gave me an idea. These things have to break in and if you keep messing with it, it doesn't get in a "rhythm". So, I opened up the RIO3100 and the output gate valve all the way and let it produce the wet useless foam. I had the collector cup empty directly back into the sump. Since it wasn't really extracting anything, dumping it back into the tank didn't hurt. This way, I didn't have 5 gallons of water pouring out of the collection cup (I went through that mess too). After a few weeks, magically it started producing junk. It's great, no adjustments necessary.


01/24/2000, 10:52 PM

If your RD3 is like mine, it will leak at the junction of the down tube where you slip on the water input/air inlet piece, hence, probably not good for outside of sump

Bill Esposito
The box said "Use Win 95 or better", I chose better so I run OS/2!

01/24/2000, 11:59 PM
I'm buying one and my plans are outside the sump also. After reading your post i'm a little concerned about leakage. Do you know if this is a common problem with them? Have you asked AE tech if this was normal?
Thanks, Duaine

Steve Richardson
01/25/2000, 01:19 PM
Again, I have the RDII, and If its built like the III, it certainly shouldnt leak.

Dirk - remember, the thing that keeps the column of foam at a particular level is the backpressure caused by the outlet in balance with the 'weight' of the water in the skimmer column. I know that doesnt help you... but hitting a 90' L right off the bat might just be enough to keep the level in the tower too high. (should just be an inch or so above the base when you first start it, right?

I too use a 90' el, but mine is plumbed straight through the wall of the sump, extends about 12" into the sump and then hits a 90' facing downward... this lets me keep the exit above the waterline, but quiets the splashing. The 12" of pipe inside the sump is also graded slightly down..not straight, so perhaps gravity is working in my favor and water is more 'falling' out of the elbow rather than being 'pushed' through it.


01/25/2000, 02:51 PM
This board is great, thanks for all the informative replies.

I agree that these things need a break in time. For first four weeks
both the input and output gate valves were fully open, and the wet
foam was directed back into the sump. After that period I started to
throttle down on the input gate valve to try and get dry foam. It now
needs to be cranked all the way to 60-70% closed to not overflow,
which caused the concern about back pressure. How much do you have to
restrict the output of the RIO 3100 before you get dry foam? I'd seen
references to 20-30% closed gate valves on this setup before, but not

I've heard reports of some ETS skimmers having assembly problems that
produce leaks. Here's a reference to one thread about an ETS 800 with
problems: http://www.escribe.com/pets/reefkeepers/index.html?mID=19216

And fixes: http://www.escribe.com/pets/reefkeepers/index.html?mID=19261

Not all ETS skimmers have these problems, but they do exist. Haven't
seen any leaks like that on my RDIII. The only leak problem I've had
was from not properly re-seating O-ring on the bottom of the
collection cup after a cleaning- user error on my part.

Having the skimmer output exit straight out, through a down grade,
then to a 90' downward turn sounds like a great way to plumb it (if
you've got the room). The output tube there sounds like it's acting as
a siphon to pull the water out more quickly, and it's quiet. Probably
even less backpressure then having it just come straight out. Maybe I
shouldn've gotten a 4 foot tank instead of a 3 foot one for the extra
room underneath . . . next time :-)

I took a close look at the skimmer again last night. Hadn't realized
it, but salt accumulation was happening in the air intake, causing it
to partially clog. Maybe the salt crust in there was forming and
breaking off causing inconsistent airflow into the skimmer. Before
cleaning out the air intake there was clear water 1 inch above the
black case in the riser tube, and now the whole riser is filled with
white foamy water. I think I'll let it keep running for a few more
weeks, keep the riser tube and air intake clean, and hope the thing
just needs more break in time.

Thanks again everyone!


01/31/2000, 10:21 PM
I put a 90 on my output but mine (whole skimmer) is in the sump. had kinda same problem...nothing happenin for a month. called john @ etss.

i am powering my rdIII w a dolphin ss800. john said open the gate all the way. adjust flow from pump until bubbles (no water)just start to fill standpipe. i thought, what the heck... he made the thing. walla...next morning, skimming like crazy. he said water in the stand pipe can kill skimming with a high flow pump. just a thought hope it helps

"Keep It Clean"

02/01/2000, 06:05 PM

To answer your question, I don't have any restrictions on either the input our output. They are both all the way open. Perhaps it's just my tank and bioload that makes that setting work for me....