Hazzard Posted February 2, 2007 Report Share Posted February 2, 2007 I have just fitted a durso standpipe to my weir in an effort to quiet things down a bit. I have followed the diagram on durso.com but cant seem to get the flushing/gurgling effect to go away. The hole in the top has been slowly made larger to test if thats the problem but with no sucess. I have also noticed that if the pipes running into the sump are just submerged the problem becomes worse but if the pipes are above water level there is to much splashing down there. Does anyone have any advice? Quote Link to comment Share on other sites More sharing options...
tel Posted February 2, 2007 Report Share Posted February 2, 2007 flushing is caused by back pressure (having pipe too far submerged) i drop my flow thru a 100 micron filter sock just above the water surface.(3000lts per hr) also you could drop it onto filter wool in a basket suspended likewise. (must change or rinse often to prevent nitrate buildup) Quote Link to comment Share on other sites More sharing options...
Hazzard Posted February 2, 2007 Author Report Share Posted February 2, 2007 The website said the same thing but also said that the pipe would have to be a couple of inches into the sump for back pressure to build up, i guess not, . I might have to try a filter sock. Quote Link to comment Share on other sites More sharing options...
lduncan Posted February 2, 2007 Report Share Posted February 2, 2007 Does anyone have any advice? Yip, ditch the durso. It's a poor design if you're looking for a quiet overflow. Quote Link to comment Share on other sites More sharing options...
Hazzard Posted February 2, 2007 Author Report Share Posted February 2, 2007 Any recommendations Duncan? Quote Link to comment Share on other sites More sharing options...
dhindry Posted February 2, 2007 Report Share Posted February 2, 2007 I initially had the same problem with my setup. I overcame it by installing a plastic ball valve under the standpipe, and slowely cracking it closed untill the water level was up near the top of the overflow. It can take a couple of hours for the water level to stablise too. I run my pipe straight down into my sump, but have cut 2 slots in it just above the water surface to let the air out. Quote Link to comment Share on other sites More sharing options...
lduncan Posted February 2, 2007 Report Share Posted February 2, 2007 I'll post a pic of my setup later today. Basically you just have a ball valve or gate valve on the plumping from the bulkhead, and tune the water level in the overflow box using it. You end up with no air being sucked into the overflow. And therefore no noise generated from the overflow plumbing. It also auto adjusts so that when the pump output changes slightly, the overflow stays silent. It's not as sensitive as the durso to tuning. That's where the durso is flawed in terms of noise. All it does is change the pressures within the plumbing to try and control to turbulence of air in the overflow. It seems to neglect the fact that the air is the problem to begin with. The best way to silence it is not to try and control the turbulence but instead remove the air altogether. I've noticed more people moving away from durso's towards this style overflow on overseas boards too. Quote Link to comment Share on other sites More sharing options...
suphew Posted February 3, 2007 Report Share Posted February 3, 2007 YOu might have too much back pressure in your pipe work to need the outlet to be below the surface. is the pipe size of the down pipe or bulkhead smaller than the durso part? It needs to be. There has been a lot of debate re durso vs full syphon systems here suggest you have a read before you commit one way or the other, I'm a fan of durso's I think they are safer and for me the noise isn't a problem over the sound of all my pumps, fans, etc. If you are running your over flow via a weir to run a full syphon system you would have to have a back up overflow pipe. Because they work by restricking the flow in the pipe if you have any blockage and no back up you will overflow your tank. Quote Link to comment Share on other sites More sharing options...
lduncan Posted February 3, 2007 Report Share Posted February 3, 2007 If you are running your over flow via a weir to run a full syphon system you would have to have a back up overflow pipe. You don't have to at all. Quote Link to comment Share on other sites More sharing options...
KP Posted February 3, 2007 Report Share Posted February 3, 2007 I run a full siphon with a backup, its better to be safe than sorry The full siphon is quite sensitive to changes in the system I would recommend using an auto topoff to keep the return pump head pressure constant. Quote Link to comment Share on other sites More sharing options...
suphew Posted February 3, 2007 Report Share Posted February 3, 2007 You don't have to at all. Could you explain please? my reasoning is simple, your are restricting the flow so if you get a blockage there will be more restriction therefore the overflow level will get higher, at some stage causing it to overflow. I'm more than will to listen to why this wouldn't be the case Quote Link to comment Share on other sites More sharing options...
lduncan Posted February 3, 2007 Report Share Posted February 3, 2007 A durso restricts the flow at a point so you MUST have a second backup overflow? Quote Link to comment Share on other sites More sharing options...
Hazzard Posted February 3, 2007 Author Report Share Posted February 3, 2007 Hmmm... lots to think about and experiment with. Thanks alot guys, look forward to seeing your setup Duncan Quote Link to comment Share on other sites More sharing options...
suphew Posted February 3, 2007 Report Share Posted February 3, 2007 A durso restricts the flow at a point so you MUST have a second backup overflow? No a full syphon restricts the flow to set the water level in the over flow so you must have a backup, unless you have the capacity in your overflow and tank to give you time to see and clear it, using a weir you wouldn't have this. The balance in a durso is adjusted using the air holes not a restriction so there is capacity built into the plumbing to allow for unplanned for restrictions/changes. Quote Link to comment Share on other sites More sharing options...
lduncan Posted February 3, 2007 Report Share Posted February 3, 2007 It's simple really. The full siphon doesn't require a backup pipe to work. You don't have to have one. Your argument was that the full siphon has a restriction so is more susceptible to blockage. But you say yourself that the duro also must have a restriction. is the pipe size of the down pipe or bulkhead smaller than the durso part? It needs to be. And if you want to get into the nitty gritty, I could argue that the reduced velocity of the water flowing in a durso system, relative to a full siphon means that the durso makes it more susceptible to blockage. But the reality of the situation is that neither overflow is safe without using standpipe covers. And, in the end, the probability of a catastrophic blockage is going to be very similar for both types of system. So you're comment that you must have a backup when using a full siphon confuses me. You don't have to have one. If you insist a full siphon does require a backup pipe, then the same must also apply for the durso. Layton Quote Link to comment Share on other sites More sharing options...
Hazzard Posted February 3, 2007 Author Report Share Posted February 3, 2007 Guys all information supplied from all sides is appreciated to us newbies. These forum threads help so many so i dont believe that varying opinions over such small issues are worth the hassle. Without the assistance of more experienced salties through these forums the hobbyist in general would be greatly deprived. Quote Link to comment Share on other sites More sharing options...
KP Posted February 3, 2007 Report Share Posted February 3, 2007 The problem is that it is almost impossible to extract any information from these debates :-? Quote Link to comment Share on other sites More sharing options...
Feelers Posted February 3, 2007 Report Share Posted February 3, 2007 Hazzard I think a full siphon plus a backup will be the quietest. Some people have very silent dursos, but there is a higher liklyhood of having noise. I think a backup is always a good idea. What $30 worth of plumbing in a marine system. Crakcer had a good write up on this, with loads of pics etc. And I'd also like to see some pics of my former tank inhabitants, if at all possible! Quote Link to comment Share on other sites More sharing options...
Feelers Posted February 3, 2007 Report Share Posted February 3, 2007 Here's crackers link I think... http://www.fnzas.org.nz/fishroom/viewtopic.php?p=101287 The "Cracker Pipe" :lol: Quote Link to comment Share on other sites More sharing options...
tel Posted February 3, 2007 Report Share Posted February 3, 2007 Guys all information supplied from all sides is appreciated to us newbies. These forum threads help so many so i dont believe that varying opinions over such small issues are worth the hassle. Without the assistance of more experienced salties through these forums the hobbyist in general would be greatly deprived. Quote Link to comment Share on other sites More sharing options...
hazymranch Posted February 3, 2007 Report Share Posted February 3, 2007 I have 2 overflow weirs and one has 2x15mm bulkheads (one unrestricted and one backup) and the other has one 25mm bulkhead. To quiet the single bulkhead weir I have to close the ball valve as Layton described. It completely silences the system because it raises the water level in the weir to the point where no vortex forms to suck air into. However, it also raises the water level in the tank to beyond where I like it. Also, if the return pump shuts off and then back on, as in a power outage, it takes the weir too long to equalize and the main tank overflows until the weir catches up and equalizes. So, I have placed the internal sponge from a return pump (I place the hole in the sponge directly over the hole in the bulkhead) over the bulkhead and it slows/diffuses the flow just enough to reduce the sound to a low gurgle without slowing it enough to overflow the tank in a restart. The double-bulkhead weir is perfect because I have one working full stop and one as a backup and the water level in the weir is enough to eliminate any air being sucked into the bulkhead but if the water level gets high enough to overflow the tank, the backup bulkhead kicks in and compensates. I have been thinking seriously about drilling another bulkhead in the 25mm weir. So, both lduncan and suphew are right. However, in my system, lduncan's solution, while completely silent, means a wet carpet in a power outage. It remains to be seen whether drilling another bulkhead in the 25mm weir will have the same effect as in the 15mm weir due to the size of the bulkhead. To be silent, there has to be a fine balance between the amount of water that gets drawn through the weir and the amount of water that the bulkhead allows through with the depth of the weir and the water level in the tank as variables in the equation. I hope this helps. I have been working through this same issue since I built the weirs almost 2 years ago. Quote Link to comment Share on other sites More sharing options...
Hazzard Posted February 3, 2007 Author Report Share Posted February 3, 2007 Hey Feelers, i'll have to take a camera over to mikes place to get a few pics. All the guys are doing great, even the anemone is happy! Quote Link to comment Share on other sites More sharing options...
Maelgrim Posted February 4, 2007 Report Share Posted February 4, 2007 My overflow runs into a 1" bulk head with some piping attached that runs into the sump. The piping has a valve that allows me to tweak the water level above the pipe in the over flow elimating the gurgling noise. Water also enters the sump submerged which reduces sump noise. No problems with power off. Overflow noise is low as the water level is high (less distance to fall), but the best way to eliminate this is have a suitably sized overflow (bigger better) so the water just runs down the walls and not gush over the top. I found this out to late, but I'm not unhappy the noise (like a mini water feature in the lounge). The main thing I fear is some crap or a fish getting into the overflow pipe and getting stuck in the valve which will end up overflowing the tank. I am working on some filtering mesh etc to prevent that from happening. Quote Link to comment Share on other sites More sharing options...
wasp Posted February 6, 2007 Report Share Posted February 6, 2007 A backup pipe is best. The guy who origionally introduced us to the "Cracker Pipe" started out using a filter to prevent blockages, but eventually discarded it as over time it caused as many problems as it solved. Having had a flood myself caused by a snail blocking the overflow pipe, and knowing of others who have had floods from various blockages, trust me, a back up spare pipe will give piece of mind, I just would not have a set up like yours without one. Using the tap restrictor method like yours, you are trading off some safety, to gain quieter operation. This is simply because the tap restrictor method does have a smaller hole than a durso. Smaller hole = less needed to block it. A back up pipe can resolve the safety problem. Quote Link to comment Share on other sites More sharing options...
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