lduncan

On multiple occasions. Don't know how low his salinity got though. Layton

That's an odd shaped tank. If it's 70cm high, then i'd go with 400W if you want to keep SPS at all levels. 250W is fine for anything up to 60cm high, more than that and 400W is better. Layton

If you want to read the original thread it's here: http://forum.marinedepot.com/Topic32610-9-1.aspx I remember reading this last week, and not knowing what to make of it. There was something about it which I though was suspicious. Maybe it's the cynic in me, but i just thought it was overly dramatic to the point of attention seeking. I could be wrong, but that's the first impression I had. But I don't know what happened, Eric and the person who sabotaged his tank, (if in fact it was actually sabotaged) are the only ones who know what happened. Layton

Analytical grade is overkill. Lab grade is good enough. Sometimes technical grade is good enough depending on the impurities in it. I'll give some places down here a try on monday, plus some of the auckland places too. Cracker where do you get yours from? APS? Layton

I'd be interested in some too. I might make some calls on monday and see who can supply it down here. Layton

If you're looking for something without any metallic internals, your generally looking at agressive gas/liquid types - which are always much more expensive. Or alternatively maybe a washing machine style valve? I think they are plastic coated internally? You could try www.rsnewzealand.co.nz (their prices are not particularly cheap, but sometimes they are more convenient to get stuff from than shipping from overseas) Layton

What you're seeing is the self regulating in action. It can be caused by varying pump output. Layton

And just as i was explaining to suphew how the durso is almost as prone to blockage as a full siphon ;-) Standpipe covers prevent blockages, not the durso design. Layton

That's what standpipe covers are for ;-)

Pretty much any industrial electrical or lighting place should have them. Radium Lamp Specialists Ideal Electrical Rexel etc Atco and Venture are a common brands for magnetic ballasts. Atco also have ceramic bulb sockets.

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: 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. No ones demanding that you rip out your durso and replace it with a full siphon. Run your tank however you want. Layton

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

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

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

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

Well the original problem the Durso was trying to solve was the gurgling and flushing noise of a standard pipe overflow. And the cause of this was the fact that both air and water were traveling down the pipe at the same time, leading to the noise. So surely the logical response to this would be to eliminate the air from the equation, which would eliminate that as a noise source. But the design of the Durso is such that all it does is control the quantity and to a degree the "turbulence" (for lack of a better description) of the air entering the overflow pipe. In my opinion this looks like a serious design flaw, after all, the intention was to solve the noise problem. Why not do it completely by eliminating the air altogether, rather than just controlling it? Layton

Nice. Like I said, if you're after a truly quiet overflow, the Durso design is seriously flawed. You know there may be some truth in my posts after all ;-). Layton

... or a heat exchange recovery system. Transfer the heat from the outgoing water back into the incoming water. It's usually cheaper to move heat, than to created it from elec or gas.

Well despite the fact that i wasn't talking to you. Yes that was the one pesonal insult I directed at you. I felt it was justified considering your behavior, and I was irritated by it. I apologised to the mod and requested that the post be removed, then took an extended break from posting on here. However it was a single isolated incident. I have not been personally insulting you for years. I've questioned some of you statements, I have asked you questions, I have corrected incorrect facts, but only once have I ever personally insulted you. Whatever, if that was true you wouldn't have posted the above. The fact is is that that was an isolated incident which i don't deny, and you are trying to incite a moderator to take some sort of action here, when it's not justified. You really just entered this thread to stir things up try and attack me, not to post of the topic, that you'll note, is in violation of the guidelines. Layton

stupid not able to edit rule :lol: It's annoying not being able to anymore.

This is not insulting and derogatory. It's the fact of the situation. Saying things like "but why advise newby's to try re-inventing the wheel, risking their live stock." is a myth, FUD, misinformation, or based on ignorance. Using a full siphon overflow is not reinventing the wheel, nor is it any more risky to livestock than a durso. It's not a personal insult. Your attempts to incite things and make mountains out of mole hills here have clearly had an effect on the moderators. My posts are on topic, and stay clear of personal attacks. I have not "attacked the messenger" like you say. From Pegasus' response, I have a genuine fear that this type of discussion will be prevented in the future. Censoring these discussions for the sake of not wanting to have a debate style discussion, doesn't encourage people to be objective, instead it encourages the blind faith, do it because everyone else does it type of response. If that's the case, why bother having a forum, if your just paying lip service to other people. I'm aware my posts rock the boat a little sometimes, because they are different, but I don't do it to be argumentative, I do it because there is a valid point there. So a quick summary, the point's i've raised are: People have different perceptions of quite. For some people the noise reduction of a durso is enough, for others it's not. The reason why the durso isn't as quite as it could be is due to the fundamental design flaw: allowing air to enter the overflow. Air and water in the overflow leads to noise. Remove the air and you remove that noise source. A blockage in a full siphon system, will likely cause a problem in an equivalent durso system. Both have restrictions and possibility for blockages to occur. The important thing is that you have other features in your overflow system to prevent blockages, the core overflow method, either durso or full siphon, does not significantly alter the risk of blockage. Overflow covers prevent blockages, not the durso system. Layton

Where did I personally insult you? Could you retract that statement. It's incorrect. Layton

Jees, no need to go crazy. I apologise for that mistake wasp, I can't edit it now. If the moderators want to then they can. It's a pain not being able to edit spelling and grammar mistakes now too. It was not intentional, so tone it down, no need to attack me. I'm trying to set straight the FUD and myths around full siphon overflow systems, and the misconceptions which clearly surround the "safety" features of the durso. It doesn't look like anyone else is prepared to do it, so I might as well. These discussions trigger people to think about things, and not just go through the motions doing what other people do, mindlessly copying. I don't know, maybe it's the engineer speaking in me. There are often a multitude of different ways to do something, if you have an accurate understanding of a variety of methods you can chose the one best one for your situation. For any situation there is always only a single best solution. However if you basing you decision on FUD, myths, or misinformation, then you don't have that opportunity. But then in that situation, I guess it's a matter of ignorance is bliss, as they say. Layton

Looks like another overly defensive person. Doesn't a durso need a restriction in it to work? There is almost as much potential for blockage there, if the usual precautions aren't taken. Also for you're perceived safety you're relying on an object not being irregular in shape for you overflow not to block. If you're worried about safety, that's not a safe assumption. For example, a pyramid shaped snail may be able to get into and part way down the overflow in one orientation, then it may rotate and become pinned, or could get trapped on the restriction at the bottom of the durso, thereby blocking the overflow. That's why covers should be used on any overflow system. But overflows have other features to stop blockages, you should not have objects capable of causing blockages getting that far into the system. You may not have said it isn't safe, but comments like "but why advise newby's to try re-inventing the wheel, risking their live stock" sure do imply it. The tap is not a flaw when normal precautions (overflow covers) are used. Well that's your incorrect perception, a durso is almost as susceptible to blockage as any other method if other features like overflow covers are not used. The restriction required by the durso is almost as bad. That's why covers should be used on all overflow systems including durso's That's what you're doing, spreading FUD. Some people might call it a myth, or ignorance. Sounds like he just added redundancy, so it's twice as safe as a single durso or other system. Personally I'm quite capable of reading and following instructions, so I don't know how your drawing that conclusion. Anyway I wonder why people tried all these other methods of regulating the airflow? There must be a reason for them to bother trying other methods. Maybe they didn't get the desired performance or noise reduction from his "one and only" method, so tried other ways? What is contradictory? Layton

What's stopping these monster snails getting into the durso and blocking it? Surely it's standard issue on any stand pipe, durso or otherwise? Is that the reason? because you have durso's? It's like saying, my overflow has never blocked because it's a full siphon. That's not the reason it hasn't blocked. The reason is either that an event has never occurred which could cause blockage, or that there are other features which prevent objects of a size capable of causing blockage to enter the standpipe. A durso design in itself does not prevent or reduce objects which could block the overflow from entering it. FUD is a generic phrase for your earlier post. I don't know the details of crackers system. But a full siphon overflow is a simple concept. I think you are putting too much faith in the perceived safety of the durso over a full siphon. In practice, there is not difference in safety. More FUD. Why two? The durso doesn't have redundancy, so why are you trying to compare two full siphon's to a single durso? It's not valid. I know how durso's work both in theory and construction. People use a variety of methods for altering the air inflow in the durso, some use straight drilled holes, some use air valves, some use slotted rotating end caps etc. Based on that I don't think you understand how it's setup, or the theory behind how it works, and automatically adapts to changing flow conditions. I've only ever had to tune it four times in the last several years. Once on setup, once after a tank move, then on installing a new skimmer on the overflow, and then again when my return pump crapped out several weeks ago. Tuning a full siphon takes literally 5 minutes max. An overflow which takes a week to set properly is clearly sensitive to changes so that means by nature it's going to be less tolerant of changing pump outputs and buildup etc. Layton