cracker

Thanks wasp...I must admit, Reefs Dursos are very quiet....(For a DURSO)!!

Just keep a close eye for a few weeks, it can creep up on you. Keep the level lower if you can until it settles.

No its all good.... Suphew, you shouldnt make out they are complex until you have seen them in operation. Infact Dursos are a lot more hard fiddly and completely untunable. I havent seen some things in operation and would never say I wouldnt go there until I had seen it.

Hows she holding up cookie?

Layton, I must agree..here, here!!

no...copy mine, with one valve underneath you had no control. nyou need the upper tuning valve.

I cant stand messy set ups....I like things tidy unlike the floor of my cars!! :-? the wife hates my cars.... :lol: note the adjusted water levels...theres only 10mm between the two levels! The red writing says: 1: dirty glass 2: solid sponge to prevent drop off 3: main tank level 4: overflow tank level

Ugly on the outside. once settled and set right, they dont need to be touched much anyway.

Note black hansen fittings at the bottom where I installed the 24mm back up pipe through the side wall.

If you are pushed for room, you can drain the overflow compartment for a few hours and drill a hole in the sidewall of the overflow and run a pipe through the wall and up the side the top. That is what i did as i couldnt get to the floor of mine, it was too awkward. I actually ended up putting a 24mm back up pipe through the side but realised it is a bit small. it works, but would be much better with more volume. Pic coming....

WELCOME TO THE "CRACKER VALVE"....

The twin valve system is great as you have 100% control over the output of your tank. You can have it as quiet, or as noisy as you wish by simply adjusting the upper tuning valve. I hope this helps the many suffering reefists who have waterfalls in their houses!!

It is a wise idea to also add another bulkhead to the floor of the overflow and install another independent pipe back to the sump. This pipe should be the same as the intake. In my case 32mm. The pipe should be a straight pipe running directly from the floor right up to 10mm below the top of the tank. It will be a little higher than the water level in the overflow that is being controlled by the twin valves. If some food or a snail semi blocks a hole, the water level may rise, This extra 32mm pipe is purely to take any extra water that is about to end up on your floor!

It is wise to spend the time on the lower valve to get it to overflow the tank the slowest amount of time possible before adjusting the upper valve. The upper valve should now be set so that the water level is just below the main tank water level. Approximately 10-20mm below. This will ensure that there is no water "Falling" into the overflow like a broken damn and creating a hell of a racket. Remember this will be the only noise to control now as the twin valve pipe is fully siphoning and full siphons have no air bubbles therefore ZERO noise. The upper valve is purely to control the final waterfalling level from the overflow comb into the overflow compartment. If you shut the upper valve too much it will start tom overflow the tank. If you open it too much it will suck the water down the overflow box too fast and end up with horrible sucking noises. The system can take a few weeks to settle in while the pipes line themselves with slime etc, so you may have to play with it for awhile.

I wouldnt say the DURSO is flawed. it is just not 100% quiet. It is still a good design if a little noise isnt a serious issue.

The twin valve pipework is glued everywhere except where it goes into the bulkhead. It can be removed from the bulkhead for cleaning etc. You should be able to reach the upper valve comfortably whilst in place otherwise it become a nuisance. The outlet bulkhead should be larger than the pipe which returns the water to the tank. for example I am running a 32mm return pipe from the sump and have a 40mm bulkhead and pipework on the twin valve pipe for the return to the sump. if you dont have this you will need to change it. Setting it up: 1: turn off return pumps and drain overflow. 2: close the upper valve fully. 3: Open the lower valve fully. 4: turn on the return pump and watch the flow. 5: With the lower valve fully open the water should rush down the fully open lower valve and the level in the overflow will not raise. 6: Slowly close the lower valve until the level starts to rise in the overflow. 7: when the lower valve is set to its correct position the water will slowly build up and start to over flow the tank. You want to adjust it so it takes about 5 or 10 minutes to achieve this. Obviously you will turn off the pump just BEFORE it overflows!! 8: Once this valve has been set, you can now run the pump system and when the level is a couple of inches from overflowing the tank you can open the smaller valve which will then start to remove the escess that the lower valve cannot cope with...

You will notice the large lower valve is attched to the "T" side of a "T" join. The upper side is then reduced down to a smaller diameter pipe and fitted with a smaller valve. The smaller valve is imperative as the tuning control. The large valve is too difficlut to control flow rates. If you turn the handle just a fraction on the large valve, you can change the flow by a few hundred litres at a time. This is too much and virtually impossible to set the overflow level. The height of the upper smaller valve should be no higher than half way up preferably, otherwise it may start to suck a whirlpool from the surface of the overflow and become noisy.

To start, your overflow needs to be reasonably generous in size... Pipes can be trimmed though to get into tight places if you are determined! Pic shows the twin valve... The larger valve on the bottom with the large red handle is the same size as the outgoing bulkhead located on the floor. This lower valve needs to be installed as deep into the overflow as possible. The reason for this is the system is a full siphon system and full siphon systems are fairly complex in the way that they start up. When a full siphon starts it starts slowly building momentum. If the larger valve at the bottom is too high up, not enough head of water is produced to kick start the siphon. This will create the problem of overflowing the tank before the tank starts to fully siphon. Water may end up on your floor for a couple of minutes before it balances.... If the valve is as low as possible, the siphon starts much faster and eliminates this problem.

I have had a request to divulge the simple Cracker pipe I designed a few months ago. This is a twin valve system designed to fit inside your overflow for easy access. No valves underneath to muck around with, so its nice and easy to adjust.

Great to hear....... Cheers for the frags too!

I have a spare screw here if you need one

similar.....more to secure the WEIR parts.

http://img.photobucket.com/albums/v238/ ... /swirl.jpg IMG tags removed. Pic far too wide. Use 600x480 Bill Mod.

They should be positioned so they swirl the surface water and push it towards the overflow.... I'll post a pic of mine...

Have a look for a white plastic screw. There should be one that you can use that will push up against the walls. Reduces vibrations.