Doc Holiday Posted June 27, 2005 Report Share Posted June 27, 2005 I'm sending my tank away to be drilled and am after some feedback. Am I better to have it drilled for 2 overflows or 1?? and is it a good idea to have the returns drilled also especially if I'm planning on having an opentop tank?? Are there any issues with having drilled returns that I should consider before doing so?? Quote Link to comment Share on other sites More sharing options...
wasp Posted June 28, 2005 Report Share Posted June 28, 2005 Drilled returns are great. You just need to install something so that if the power goes off it will not syphon all the way down to the level of entry in the tank. What I have done is raise the return pipe, outside the tank, to above the water level, install a coupling at the high point with a small tube running off that goes to the tank, just below water level, but only just. If the power goes off, as soon as the tank water drops below this small tube, air is sucked into the return pipe and breaks the flow. Not sure if that is standard procedure, but it does work nicely. Twin outlet drilled holes are also good in that you can have a point of safety, ie, if one was blocked by a snail or some other accident, you still have the other working. You would need some means to detect if one was blocked, like the tank level suddenly went up 1/2 inch, or something like that. IMO, if you are going to the expense and hassle of sending the tank away to be drilled, get all the holes you think you may need, you can plug them if need be, but they will always be available for you. Quote Link to comment Share on other sites More sharing options...
Brianemone Posted June 28, 2005 Report Share Posted June 28, 2005 only issue for the returns is the height. im havent decided whether or not to drill mine as im not sure if im getting a seaswirl or not Quote Link to comment Share on other sites More sharing options...
Doc Holiday Posted June 28, 2005 Author Report Share Posted June 28, 2005 Drilled returns are great. You just need to install something so that if the power goes off it will not syphon all the way down to the level of entry in the tank. What I have done is raise the return pipe, outside the tank, to above the water level, install a coupling at the high point with a small tube running off that goes to the tank, just below water level, but only just. If the power goes off, as soon as the tank water drops below this small tube, air is sucked into the return pipe and breaks the flow. Not sure if that is standard procedure, but it does work nicely. Twin outlet drilled holes are also good in that you can have a point of safety, ie, if one was blocked by a snail or some other accident, you still have the other working. You would need some means to detect if one was blocked, like the tank level suddenly went up 1/2 inch, or something like that. IMO, if you are going to the expense and hassle of sending the tank away to be drilled, get all the holes you think you may need, you can plug them if need be, but they will always be available for you. couldn't you just put in a non return valve rather than going to all that trouble?? Quote Link to comment Share on other sites More sharing options...
Drifty Posted June 28, 2005 Report Share Posted June 28, 2005 I have drilled my return and then split it to two seaswirls, have two overflows, one to the skimmer and the other to the refugium Quote Link to comment Share on other sites More sharing options...
suphew Posted June 28, 2005 Report Share Posted June 28, 2005 Non-return valuse reduce your water flow, plus are prone to getting stuck open if for example a snail or algae etc gets into it. I didn't want to risk setting up a syphon with my returns, my tank had two holes in the back which were used for returns via a SCWD I drilled the bottem of the tank and used these with a closed loop and ran my return over the top. I think connecting the return to a seaswirl is the best idea I have seen unfortunely I don't have room to mount one. It all really comes down to the "sleep at night" factor, Short of the plumbing coming apart (and it is all glues pressure piping) I KNOW I can turn off any or all of my system and not have a problem. Quote Link to comment Share on other sites More sharing options...
chimera Posted June 28, 2005 Report Share Posted June 28, 2005 if i had designed mine again, i would have done single overflow outside the back in the middle. also would have considered drilling the returns (however, my preference would still be the sea-swirls). i did a quick pic to show you what i would have liked... (alternately, leave the 2 return holes undrilled and have 2 sea swirls instead) many on reefcentral, ultimatereef etc are getting their tank overflows done like this. twin overflows is way overkill for a 5 footer, it will just cost you more money for glass and plumbing. waste of time. Quote Link to comment Share on other sites More sharing options...
Pies Posted June 28, 2005 Report Share Posted June 28, 2005 Single overflow for sure, I have a single and my tank is 1400 litres. I have duel on my 5 footers and its overkill. Make it a big hole though 40mm + Chimera - I looked at a single external overflow for my tank as well. The tanks you are talking about (at least the ones i've seen) are all acrylic. Notching out the glass would cause severe issues with the strength of the overall tank design. Also the necessity of the center brace makes it a bit impracticial for glass tanks. I talked to Peter and Port Nicholson Glass about it and he refused to do it because of the issues with glass strength. Pie Quote Link to comment Share on other sites More sharing options...
wasp Posted June 28, 2005 Report Share Posted June 28, 2005 couldn't you just put in a non return valve rather than going to all that trouble?? Good point Doc, however I'd go with what Suphew said 100%. What I set up is very little hassle, nothing in it against a non return valve. But the main things is, this is all about safety and "sleep at night" factor. Installing an anti syphon type air inlet is as full proof as you can get, whereas non return valves can be prone to get stuck open, you only need a little bit of calcium on it and it will leak. If you do a search on RC with a word like "flood", or similar, you will find that many of these events come back to non return valves that did not do the job, IMO anyway, it is better to design them out of the system. Quote Link to comment Share on other sites More sharing options...
wasp Posted June 28, 2005 Report Share Posted June 28, 2005 if i had designed mine again, That's funny Chimera :lol: , it's a rule of reefkeeping, that no matter how carefully we design our tanks, after it is all finished we wish we could change something on it ! Quote Link to comment Share on other sites More sharing options...
chimera Posted June 28, 2005 Report Share Posted June 28, 2005 but of course dude, it's also the same as life,... no regrets, you make do with what you have! pies, im not so sure on the strength issue - what if you had two centre braces, one on each side of the 'notch'. i cant see how the glass strength would be worse if you had these. the pressure is greatest at the bottom, not the top. if anyone can explain otherwise, im open ears! Quote Link to comment Share on other sites More sharing options...
Doc Holiday Posted June 28, 2005 Author Report Share Posted June 28, 2005 It sounds like a good idea Chimera but I wouldn't even attempt for the same reasons Pies mentioned, but I do like the Idea of the centre overflow though. I'm trying to get away from having any plumbing from going over the top of the tank because it will be topless with pendant lighting. am i better to have the returns just below the water line? I havent considered sea swirls at this stage of the game. Quote Link to comment Share on other sites More sharing options...
Pies Posted June 28, 2005 Report Share Posted June 28, 2005 Chimera - no doubt the most pressure is at the bottom, but when my center brace came un-glued on my 5 footer there was maybee 2 inches of deflection at the top of the tank, which puts a MAJOR bow in the 10mm glass. If I had the notched overflow no doubt it would have just split. Pie Quote Link to comment Share on other sites More sharing options...
wasp Posted June 28, 2005 Report Share Posted June 28, 2005 True. The weak point is top middle. (If no brace) The safest place is bottom corners, although perhaps harder to actually drill. Quote Link to comment Share on other sites More sharing options...
SteveA Posted June 28, 2005 Report Share Posted June 28, 2005 That's funny Chimera :lol: , it's a rule of reefkeeping, that no matter how carefully we design our tanks, after it is all finished we wish we could change something on it ! Not me. Would use exactly the same design. Even if I were to make it bigger, I would not change the basic design. Mind you , it has taken a few tank builds, over the years, to get there. Steve Quote Link to comment Share on other sites More sharing options...
Pies Posted June 28, 2005 Report Share Posted June 28, 2005 Given the location of my tank nothing I would really change, lighting, plumbing etc are all spot on. Pie Quote Link to comment Share on other sites More sharing options...
chimera Posted June 28, 2005 Report Share Posted June 28, 2005 ...but when my center brace came un-glued on my 5 footer... ok, but when you have a tank you're working on the fact that the centre brace(s) doesnt become unglued... EVER. would two thinner centre braces either side of the overflow work then? or even a PSR (pies steel rod) special? i think strength would be just as good, and given two centre braces rather than a single central one, would give some good redundancy just incase the worst happened and one did become unglued. touch glass. Quote Link to comment Share on other sites More sharing options...
Ira Posted June 28, 2005 Report Share Posted June 28, 2005 If I was to do my tank over I'd get a nice steel framed stand instead of a ghetto one and it'd be deeper and maybe a bit less tall. And I'd have an in sump skimmer and either drilled returns or a sea swirl(Can still do that easy enough) And the sump would be rearranged and and and and... Quote Link to comment Share on other sites More sharing options...
Pies Posted June 28, 2005 Report Share Posted June 28, 2005 Chimera - Honesly I don't know, and I know what your saying. Have you ever put a straight edge along the front center of your tank? How much deflection do you get? I guess this is the key. Personally I think its a bit of a kamakazi pilot idea and wouldn't consider it myself. Not sure if the PSR system would make it better or worse. I do know that glass is incredibly strong, but it doesn't take much to break it if pressure it put in the right place, and I see the 'overlflow cutout' being a likley place to start a crack. Maybee it would work, but how would the SAN factor be (Sleep At Night). Pie Quote Link to comment Share on other sites More sharing options...
SteveA Posted June 28, 2005 Report Share Posted June 28, 2005 I think with an overflow design like that you would want to install a float switch on your floor and connect is to a device to send you a text massage WHEN the tank let go. You might at least get home in time to save some of your corals that way. Steve PS: I have also had a center brace let go on my last tank. New one uses Pies' steel rods. Quote Link to comment Share on other sites More sharing options...
chimera Posted June 28, 2005 Report Share Posted June 28, 2005 but how would the SAN factor be :lol: only reason i ask is that i see alot of tanks on reefcentral being made this way - and they ARE made of glass. most opting for this method to gain extra space inside the tank. i'll see if i can dig up some links... Quote Link to comment Share on other sites More sharing options...
klaymann Posted June 28, 2005 Report Share Posted June 28, 2005 Check out Reefs overflows on his "mother" of a tank , have used this system on clients tanks and works brillantly with bugga all sound and no drainage.... Quote Link to comment Share on other sites More sharing options...
Pies Posted June 28, 2005 Report Share Posted June 28, 2005 Chimera, got any links to glass tanks in that configuration? I'd like to see how they did it. I've only seen it done on acrylic tanks so far. SAN Pie Quote Link to comment Share on other sites More sharing options...
wasp Posted June 28, 2005 Report Share Posted June 28, 2005 :lol: only reason i ask is that i see alot of tanks on reefcentral being made this way - and they ARE made of glass. most opting for this method to gain extra space inside the tank. i'll see if i can dig up some links... Not sure, but I wonder if it could be done by using an XX extra thick piece of glass, or toughened glass? However in Doc Holidays case he does not have that option as the tank is already built, and he needs something to work with what he has got. What's wrong with a corner overflow anyhows? Quote Link to comment Share on other sites More sharing options...
Ira Posted June 28, 2005 Report Share Posted June 28, 2005 Because it uses up tank space...IMO, you should have that overflow cut out of the back extending out what 3"? Like in the picture, but then extend the sides to the left and right of it back 3" also...No point wasting that empty space to the sides of the overflow when you could fill that up with tank. Quote Link to comment Share on other sites More sharing options...
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