cracker Posted April 23, 2006 Report Share Posted April 23, 2006 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. Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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. Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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. Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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... Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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. Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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! Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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!! Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 WELCOME TO THE "CRACKER VALVE".... Quote Link to comment Share on other sites More sharing options...
tel Posted April 23, 2006 Report Share Posted April 23, 2006 cracker i have seen your system and cant believe how silent it is. when i visited you mentioned the possible need to have another '' spare '' return pipe for safety. is this necessary as your system could be prone to blockage/snails etc more than a durso? . im keen to try it but cant add another spare standpipe.has cracker got this ''spare''?? Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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.... Quote Link to comment Share on other sites More sharing options...
tel Posted April 23, 2006 Report Share Posted April 23, 2006 i cant see how i can with mine. do you know what cracker has done ? is it possible without or too unsafe?? Quote Link to comment Share on other sites More sharing options...
lduncan Posted April 23, 2006 Report Share Posted April 23, 2006 Interesting design. One question, why not have the valves on the outside of the tank instead of on the inside of the overflow? That's effectively how I run it (except with one valve rather than two). The two valves is an interesting idea. One for coarse adjustment, the other for fine tuning. Layton Quote Link to comment Share on other sites More sharing options...
tel Posted April 23, 2006 Report Share Posted April 23, 2006 Layton, do you run yours with a single standpipe?? Quote Link to comment Share on other sites More sharing options...
lduncan Posted April 23, 2006 Report Share Posted April 23, 2006 Yip. But with overflow covers to prevent anything large entering the standpipe to cause blockage. Durso's are almost as prone to blockage to these systems. Either way, if your worried about blockage, you should be using standpipe covers to prevent it. Layton Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 Note black hansen fittings at the bottom where I installed the 24mm back up pipe through the side wall. Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 Interesting design. One question, why not have the valves on the outside of the tank instead of on the inside of the overflow? That's effectively how I run it (except with one valve rather than two). The two valves is an interesting idea. One for coarse adjustment, the other for fine tuning. Layton Ugly on the outside. once settled and set right, they dont need to be touched much anyway. Quote Link to comment Share on other sites More sharing options...
tel Posted April 23, 2006 Report Share Posted April 23, 2006 i tried running a full siphon with one standpipe. if i turned my return pump off and then on again i had overflows. this happened because i didnt have spare height in the box to build up pressure to start it to self regulate(i think). i had kept the valve (exterior underneath the tank) restricted to such an extent to keep the box full and eliminate the waterfall noise. i think i will somehow build a ramp? to stop the waterfall and then try again with the box 1/2 full. comments ?? Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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 Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 i tried running a full siphon with one standpipe. if i turned my return pump off and then on again i had overflows. this happened because i didnt have spare height in the box to build up pressure to start it to self regulate(i think). That would be right i had kept the valve (exterior underneath the tank) restricted to such an extent to keep the box full and eliminate the waterfall noise. i think i will somehow build a ramp? to stop the waterfall and then try again with the box 1/2 full. comments ?? no...copy mine, with one valve underneath you had no control. nyou need the upper tuning valve. Quote Link to comment Share on other sites More sharing options...
lduncan Posted April 23, 2006 Report Share Posted April 23, 2006 i tried running a full siphon with one standpipe. if i turned my return pump off and then on again i had overflows. this happened because i didnt have spare height in the box to build up pressure to start it to self regulate(i think). i had kept the valve (exterior underneath the tank) restricted to such an extent to keep the box full and eliminate the waterfall noise. i think i will somehow build a ramp? to stop the waterfall and then try again with the box 1/2 full. comments ?? Well you can run these systems without any standpipe in the overflow. It depends how much water you can afford to hold in the sump when the power is off. So then you can adjust the valve and set the water level in the box to wherever you want it to be, obviously the higher up the less noise from the actual water overflow, but the less tolerance there is for self regulation when pump output increases. Layton Quote Link to comment Share on other sites More sharing options...
lduncan Posted April 23, 2006 Report Share Posted April 23, 2006 no...copy mine, with one valve underneath you had no control. nyou need the upper tuning valve. You can get the same effect with the two valves on the outside. All you're doing is altering the pipe area so that the flow rate out is matched to the return pump at a specific water level and pressure. One valve is fine, but if you use two, like in your configuration (one large, one small) i guess it's easier to tune to tight tolerances (more precision in the water level in the box). Layton Quote Link to comment Share on other sites More sharing options...
suphew Posted April 23, 2006 Report Share Posted April 23, 2006 i'm a little confused, I understood from other posts that siphon systems were as safe, easier to tune, less complex, and cheaper than durso's?? Layton but the less tolerance there is for self regulation when pump output increases. cracker once settled and set right, they dont need to be touched much anyway tel if i turned my return pump off and then on again i had overflows Classic stuff, love it, think I will stick with the seriously flawed durso for now. Quote Link to comment Share on other sites More sharing options...
lduncan Posted April 23, 2006 Report Share Posted April 23, 2006 i'm a little confused, I understood from other posts that siphon systems were as safe, easier to tune, less complex, and cheaper than durso's?? Layton looks like you've picked up wasp's nasty habit of taking things out of context to try and shoehorn it into something it's not. What I said in full was: you can adjust the valve and set the water level in the box to wherever you want it to be, obviously the higher up the less noise from the actual water overflow, but the less tolerance there is for self regulation when pump output increases. Which you've assumed means that the system has tight tolerances. What it really means is that you can tune the system to run at exactly whatever tolerance you want. As far as my system goes it's as safe, far easier to tune, less complex, and cheaper than a durso. Classic stuff, love it, think I will stick with the seriously flawed durso for now. No ones demanding that you rip out your durso and replace it with a full siphon. Run your tank however you want. Layton Quote Link to comment Share on other sites More sharing options...
wasp Posted April 23, 2006 Report Share Posted April 23, 2006 looks like you've picked up wasp's nasty habit of taking things out of context to try and shoehorn it into something it's not. Layton Sheesh! Here we go again. Why do you keep dragging my name into your unseemly arguments Layton? And for that matter, why is nearly every thread you are in turn into an argument that ends up being moderated? Quote Link to comment Share on other sites More sharing options...
cracker Posted April 23, 2006 Author Report Share Posted April 23, 2006 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. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.