Pies Posted January 5, 2004 Report Share Posted January 5, 2004 I would like to move my plumbing for my tank into the garage. The fishtank is also downstairs. This means I can't use gravity. So what I need to know is how to use 2 pumps, one to send water to the sump, 1 to return it to the tank. The sump will be over 500 litres in size. I need a system that will ensure that the tank cannot be overflowed. That is the sump overflowing the tank, or the tank overflowing the sump. also needs to be safegarded against a single pump failure or power outage. Experance, diagrams or links please. Pies Quote Link to comment Share on other sites More sharing options...
count_sexy_tart Posted January 5, 2004 Report Share Posted January 5, 2004 why not y join the two pumps so that they run with each other that way you have one inlet and one outlet and if a pump fails the other will still be running and then the only risk is a possible blockage on the inlet to the pumps Quote Link to comment Share on other sites More sharing options...
Pies Posted January 6, 2004 Author Report Share Posted January 6, 2004 Sorry I don't understand? How can I join them together? 1 has to pump water from the tank, into the garage. The other from the garage into tank. Imagine have to tanks in your living room, then tank the lids off. Now pump water from tank 1 into tank 2. Then pump water from tank 2 into tank 1. Once you have this going, stop pump 1. What happens? Disaster. Quote Link to comment Share on other sites More sharing options...
Ira Posted January 6, 2004 Report Share Posted January 6, 2004 You could adjust the levels of the intakes on the two pumps so that when the water level of the sump gets low enough(And the tank almost overflowing) it starts sucking air instead of water and stops. Then do the same on the other end. Once enough water flows back it should start pumping again. Or use a couple of float switches to switch off the pumps if the water gets too low. Quote Link to comment Share on other sites More sharing options...
Interfecus Posted January 6, 2004 Report Share Posted January 6, 2004 If the tank is on a stand and the sump is on the garage floor then shouldn't there be enough of a drop to use an overflow on the tank? If the tank is lower than the sump then the opposite could be used. Only one pump would be needed to pump the water back the other way. Quote Link to comment Share on other sites More sharing options...
JackJackJack Posted January 6, 2004 Report Share Posted January 6, 2004 thats true, but if there is a big distance horizontally between the two then it would have to be a fair vertical drop to push the water at a decent flow rate, unless you want to drill in 90mm stormwater overflow into your tank hehe. the two pumps would be pretty dangerous if one failed. the only way i can see that working is if you use iras idea and have the intakes for each at the desired water levels in the sump and the tank. but thats going to create alot of noise as they suck air, and does anyone who knows more about pumps know whether this would damage the pumps? as they would be running half dry for alot of the day. nowhere upstairs you can put your sump? Quote Link to comment Share on other sites More sharing options...
Ira Posted January 7, 2004 Report Share Posted January 7, 2004 They shouldn't suck air constantly. The idea is that under normal operation the intakes are well under water. At least an inch or two anyway. That should be sufficient that they wouldn't suck any air normally. But if for example the tank>sump pump fails(Or just is out of balance and out runs the sump>tank) the tank water level will drop just enough to stop. If the sump is going to be over 500L that gives quite a bit of leeway and both the tank and sump should have enough extra room for 2-3" of water or an extra hundred liters. Quote Link to comment Share on other sites More sharing options...
Interfecus Posted January 7, 2004 Report Share Posted January 7, 2004 You could also rig up a water detector (just two wires almost but not quite touching) just below the top of the tank and the top of the sump that switches the pumps off if triggered. The parts shouldn't cost too much. Quote Link to comment Share on other sites More sharing options...
MGilchrist Posted January 7, 2004 Report Share Posted January 7, 2004 normally closed float switches, one in sump and one in tank, run wiring in series to a lv relay that will drop off power to pumps if either tank is low. Quote Link to comment Share on other sites More sharing options...
Joze Posted January 7, 2004 Report Share Posted January 7, 2004 have been thinking about this as I need to do something about mine...2 external filters totalling 4500lph isnt enough. So far the plan is.......warehouse pool pump...cartridge filter type and somehow build a sealed sump or a spa sand filter. Works out miles cheaper than a pump equivilent. I am going to talk to an aquaintance who has experience in building uv filters about building one into it. Damn tank has a phospate problem, I suspect our water supply is 80% of the problem. Quote Link to comment Share on other sites More sharing options...
Pies Posted January 7, 2004 Author Report Share Posted January 7, 2004 Some interesting comments. Both the sump and the tank are not 'sealed', nor will the by. Everything will have open lids. IRA. A good start, but what stops the sumps from being overflowed in the event of 1 pump failure? Remember the sump is going to have 500+ litres of water in it. Interfecus. As per my description there is no way to use gravity in either direction. Infact the water will be going up and down, and traveling about 10m. If I could use gravity I wuldn't be in this position of using 2 pumps. but it IS the only way it can happen. A water detector is a good idea! I may use something like this to be hooked up to an alarm or computer. MGILCHRIST. Float switches are completely out of the question. Saltwater is VERY corrosive, and there are dozens of examples of tanks being wiped out because of float switches not working (sticking on or off). There are some nice computer controlled water detectors which would be nice as a backup though. e.g. when water level is x then turn on/off pump and sound alarm. JackJackJack. The width of the pipe will not increase the flow rate, and larger pipes will slow down the flow rate is surface contact area in increased. Joze. You have a marine system? Tell us more about it As for pool pumps, just watch anything with metail inside. Some pumps with metal inards are OK (grunfos??? sp?) but need to be grounded other wise a rust layer will form and algae can be produce by the electrical current through the water. It is quite possilbe that your water supply has phosphates in it. I assume you mean for freshwater top/off and salt mix? If so, invest in an RO & DI filter. Not cheap ($500) but will prevent all Nitrate and phosphate (as well as sediment and anything else for that matter). Phosphates are killers. Also if you are feeding frozen/fresh food beware as these foods have a lot of phosphate in them. Keep the ideas comming. Pies Quote Link to comment Share on other sites More sharing options...
Ira Posted January 8, 2004 Report Share Posted January 8, 2004 With my idea, if one pump fails the other one will drain its own tank and stop once it gets low enough and before the other gets too high. It'll sit there dry for a while until you fix it, but I don't see another way if you don't want to use float switches. If the sump's pump fails you should still get some flow siphoning from the sump into the main tank, just probably very reduced. Although, if it's going to be about 1 floor up you could actually get heaps of flow. Quote Link to comment Share on other sites More sharing options...
Joze Posted January 8, 2004 Report Share Posted January 8, 2004 Its not marine but it might be worth looking at pool pumps for salt water operation, I guess since salt water pools have become popular the possibility of pumps and filters for salt use is a possibility. For some base figures.......a brand new sand filter (plastic) is $700 an aquatic pump that can push anywhere near the same amount........$1000+. How does the national aquarium pull off filtration? I guess in some of the tanks using sea water wouldnt be a good idea. Quote Link to comment Share on other sites More sharing options...
Pies Posted January 8, 2004 Author Report Share Posted January 8, 2004 I don't think the National Aquairum pulls of filteration at all. They use a well, and dry salt from there (which is filters through the sand/gravel of the beach) and pump out too sea... So water is always circulating. IWAKI pumps are good for saltwater, and can be picked up reasonably. I got a 8000 liter an hr IWAKI pump 2nd hand is perfect order for $200.00. And I am getting another for the same price. These are all plastic inards but not submersable. IRA. How do you ballance the water level in the tank? (so its not rising or falling but remaing constant? Quote Link to comment Share on other sites More sharing options...
MGilchrist Posted January 8, 2004 Report Share Posted January 8, 2004 pies i did not mean to put metal in tank, would suggest using something like a magnetic proximity switch, one side plastic coated in tank with float, other side outside tank, attached to wiring these switches are frequently used as limit switch and should suit. Mark Quote Link to comment Share on other sites More sharing options...
Ira Posted January 9, 2004 Report Share Posted January 9, 2004 When I went on the tour of the national aquarium a few months ago they didn't go into too much detail on the filtration. I think they said they've got an intake out in the ocean, countinuously changing the water in their big tank which is also run through 4 MASSIVE sand filters. For their smaller tanks I think they also have a small sand filter(Not sure on this) and something like a dozen UV sterilizers on the return from each of them going to a main sump and then back out again. Something like that anyway. Not quite sure how you'd make the water levels stay constant be MUCH easier with an overflow. Might have to use ball valves to get it close enough and just let the pumps suck air occasionally and stop for a moment if it gets ahead. Obviously float switches like Mgilchrist suggests would be preferable to just turn them off for a minute. Quote Link to comment Share on other sites More sharing options...
Pegasus Posted January 9, 2004 Report Share Posted January 9, 2004 http://homepages.paradise.net.nz/grumpygr/AUTOFILL.htm Room for thought Quote Link to comment Share on other sites More sharing options...
Warren Posted January 9, 2004 Report Share Posted January 9, 2004 Me confused! The only reason you can't use gravity is if the tank and sump are at exactly the same level. If there is a difference then gravity can be used. If you really want to use 2 pumps the is only one way if you want to do it properly. You'll need to speed control the pump that does the least work and use level sensors in both tanks. The integral of the rate of change in level difference between the tank and sump will control the flow of the pump with the lighter load. It's using a simple control (PID) loop to control the flow. You'll need to put an AC drive on one pump (yes, it can be done on single phase - especially on pumps) and have a fairly basic 2 input PID controller + 2 linear level sensors. Total cost is likely to be about $2000 (at mates rates). If the controller goes into alarm it can stop both pumps and flow valves if need be. I still think you can use gravity, especially if there is a level difference in between the tanks... 8) Quote Link to comment Share on other sites More sharing options...
Pies Posted January 9, 2004 Author Report Share Posted January 9, 2004 There will be between 1 and 2 feet of difference in height over 8-10 metres. Because of the layout of the house, piping in both directions will have to go both above and bellow the tank. Warren: I know I can still use gravity if there is a difference, but as soon as you go 'up' then its stops being gravity and starts being a syphon. If for any reason the syphon stops, then I am in the 'poo'. Also if there is not much difference in heigt, then the flow is less. I am looking at wanting to turn about 5000 litres an hr through the sump. I just don't see any other way than using 2 pumps. The 'ultimate' would be a 'water changer' peristellic pump, but they don't make them turn enough water over in my price range. I have been speaking to some people in Australia who do a similar thing, requiring 4 tanks (tank, sump, and a feeding trap level automater type tank for each). I think I am likley to do this. I don't like the idea of putting the saftey of my tank into the hands of a single switch of float. Although I think that I would be happy to use device like this for alarms or potentially for 'cut off' emergenciey switches, but not as part of the controll mechinisim. If I pump runs dry and blows up, I don't care, as its cheaper than loosing 3 pieces of coral. If I am missing something (which I may as I failed science at school) let me know or draw me a picture. Everything must be designed to save the tank and the house. Overflows in the garage are undesirable but more acceptable. Cheers Pies Quote Link to comment Share on other sites More sharing options...
Warren Posted January 9, 2004 Report Share Posted January 9, 2004 Going up and down with the piping is no problem and it won't siphon if you put an air trap at the lower end. You have a completely sealed pipe all the way to the lower end then raise it up to the level of the higher tank. At this point you create an overflow, so yes it is a siphon till this point but then it turns into an overflow. Just an bigger version of the hang on tank overflow systems. You'd be fine using gravity if you used a fairly big pipe (60-75mm would do it). A bit of big pipe would be much cheaper and more reliable than a control system. I'll email a pdf picture to you... Quote Link to comment Share on other sites More sharing options...
Pies Posted January 11, 2004 Author Report Share Posted January 11, 2004 Thanks for that warren. I might try and draw a diagram, with house schematic etc so its clear what I am doing. Look forward to the .pdf. Pies Quote Link to comment Share on other sites More sharing options...
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