Megaflow durso issues???

[Raf]

I have a potential problem with this tank I look after. It uses Megaflow overflows with durso standpipes. When we set it up, I guess the floor was a hair unlevel(by about 2mm off on a 6 foot length) and more water seems to be flowing in one overflow than the other. At first, i thought the air flow was blocked on the one cap, but that was not the case.

Well, the problem is, the one durso is making gurgling noises as air is getting into it and the water level in that overflow is much lower. Thing is, these durso caps have these holes drilled into them where the cap elbow meets the standpipe, i guess in case the screen ever got clogged, the holes would act as the drain. So anyways the water level never goes above these 3 holes and actually drains through them instead of going in the screen of the durso elbow....

So, how would I go about fixing this. The drain lines have no valves so I cannot slow the flow on the one overflow. Should I try and find a durso cap that doesn't have thes holes drilled?

suggestions?

thx :)

note, in the link pic you can kinda see these holes in the elbow unit of the durso...
http://akamai.edeal.com/images/catalog3684/folder24579/img3039906med.jpg

link to larger pic:
All-Glass Mega Flow Overflow Accessory Kit at Big Al's Online (http://www.bigalsonline.com/BigAlsUS/ctl3684/cp18671/si1378885/cl0/allglassmegaflowoverflowaccessorykit)

[Pescador]

Are these the adjustable height version's of the Megaflows? You might be able to tweak it that way if they are. I don't quite get how the side holes work a regular durso only has the one in the top.

[Chin_Lee]

cut the durso that is a little higher by 1/16" increments until they are doing their own share of draining.
if the holes are too big, epoxy a couple of them to plug them up.

[fkshiu]

It would involve a bit of work, but have you ever tried the "Herbie" system which works well for megaflows? Here's a few pics of mine in my external overflow box:

http://i27.photobucket.com/albums/c197/fkshiu/IMG_5560.jpg

http://i27.photobucket.com/albums/c197/fkshiu/IMG_5561.jpg

One hole is used as the main drain (the short one) while the other taller standpipe is the emergency drain. The main drain flow is adjusted with a gate valve until the water level is just at a trickle going down the emergency drain. Water return from the sump goes up and over the back of the tank.

Took a bit of adjusting, but now it's dead silent. All I hear is the hum of my skimmer.

[Raf]

Thanks for the tips.

Yeah, these are adjustable but when I lower one, the level just goes down to the new level and still drains down these holes. Not sure the function of these holes but they are PITA!

I may have to plug them or make a DIY durso cap.

[Moose]

The gurgal sound could be air trapped in the line I had the same drain lines before and that would happen some times. I would put two ball valves on the drain lines one each that is so you can regulate the levels in the overflows without having to cut anything and as well this will most likely cut back the nose especially if you run the water high in the overflows. The holes are there to prevent back syphoning and should not be under water just the screen on the elbow

[Lofus]

I'm having the same issue with my Megaflow durso. I've just moved to a 92 corner with then overflow in the back corner and talk about your insane gurgling noises!

I had a DIY durso in the old tank that worked great. I suspect its those extra holes in the sides that are causing the issue. Anyone have any luck getting them to work quietly?

Jim