BaZ Posted May 2, 2006 Share Posted May 2, 2006 Ok I just saw the tank size back on page 1. It's an 800L tank with an 8000L pump. While excessive by normal standards, this is not too rediculous. Depending on the head height it is probably only turning the tank over 6-7 times an hour. He could certainly get away with a smaller pump I agree, but it shouldn't be the only way to fix the problem. I have a tank with sump in my loungeroom which is turned over at a similar rate to this. Link to comment Share on other sites More sharing options...
Nigel Posted May 2, 2006 Share Posted May 2, 2006 I thought 2 x 25mm stand pipes could handle 8000lph - I thought they did 4000lph each & with head height on the pump she'd be only putting out about 7000lph anyway? Not even close the best you would get is a little under 2000lph through both. Link to comment Share on other sites More sharing options...
BaZ Posted May 2, 2006 Share Posted May 2, 2006 But this means his sump should run dry and the tank should overflow if the return pipes are too small. Correct? Link to comment Share on other sites More sharing options...
Ash Posted May 2, 2006 Share Posted May 2, 2006 huh? I setup two of a buddy's 8x2s with a 6000lph each & two 25mm standpipes, surely it would be flowing more than 2000lph total, even with about 1600mm head height I would have expected closer to 5000lph by the graph on the box. That would have to be at least 2500lph each. My 4x2's have a 2400lph & a 2800lph on each of them, they'd be closer to 1800lph & 2000lph actual output by the graphs on their boxes too, with single 25mm standpipes. I'm talking internal diameter BTW, isn't everyone else? Sorry to go off topic. Link to comment Share on other sites More sharing options...
Nigel Posted May 2, 2006 Share Posted May 2, 2006 I must me misunderstanding what Bruce is telling us then. I have all the tanks in the quarantine room with one 25mm pipe in them and its not easy to get much of a flow rate through them. I dont trust flow rates on pumps I think they are always less than what they say. Link to comment Share on other sites More sharing options...
BaZ Posted May 2, 2006 Share Posted May 2, 2006 I dont trust flow rates on pumps I think they are always less than what they say. ← Too right! So I don't understand why you say that the pump IS too big when we don't even know how much it is pumping. All we can really assume is that it is pumping 8000L max, at zero head. Link to comment Share on other sites More sharing options...
Ash Posted May 2, 2006 Share Posted May 2, 2006 hey Nigel are those 25mm bulkheads horizontal or vertical? makes a huge difference! Link to comment Share on other sites More sharing options...
Bruce Posted May 2, 2006 Author Share Posted May 2, 2006 Ok, I don't need a return pipe back to the sump. I don't need more water in it. It's problem is being too full. The pipes are only 20mm pressure pipes. The sump is 4ftx16"x18". Overflow down the pipes isn't quick enough to handle the pump speed but siphon is too quick for the pump. So I need to find the perfect balance of a restricted siphon to control speed. This is nearly impossible to do though. Bruce Link to comment Share on other sites More sharing options...
Josh Posted May 2, 2006 Share Posted May 2, 2006 How can the falling be to weak and the siphon to strong? I have only heard bad things about over flow boxes Why dont you get a smaller pump. It would be cheaper then two overflow boxes Josh Link to comment Share on other sites More sharing options...
BaZ Posted May 2, 2006 Share Posted May 2, 2006 Overflow down the pipes isn't quick enough to handle the pump speed but siphon is too quick for the pump. There should be no syphon. Gravity is the only thing which should be bringing your water back to the sump. Link to comment Share on other sites More sharing options...
Caesar Posted May 2, 2006 Share Posted May 2, 2006 Ok, Sorry for coming in half way thru this post but I don't understand. I take it from your pictures that the setup you have is 8000l/hr pump drawing from your sump and pumping into the tank. Then as this overflows into your pipes back to the sump? Firstly the extra power of the pump doesn't seem to be an issue to me. If so the sump would be pumped drynot becoming overflowed. Secondly, the only way that the sump can be filling is if the power of the pump isn't greater than the siphon effect (of which an 8000l should be). Otherwise the siphon effect would only take place and the sump would overflow if the power is off. Therefore lets look at your drainage pipes. Best solution is to get rid of the cross beams on your down pipes. Have the pipe just stand vertically with the cap off therefore, you fill your tank up to the top of the pipes and fill up your sump. When you turn the pump on the water flows into the tank and the overflow falls down the pipe. Therefor ethe sump cannot overfill as it can only get the overflow from the tank. This also stops the siphon effect because once the water drops below the top of the pipe it cannot be siphoned any further. Only issue is it does produce a gurgling effect which someone else provided details on how to overcome. I have several sumps running on my system like this. If someone can tell me how to post pics I will show you one of my setups. Ave Jason Link to comment Share on other sites More sharing options...
Nigel Posted May 2, 2006 Share Posted May 2, 2006 hey Nigel are those 25mm bulkheads horizontal or vertical? makes a huge difference! ← There vertical but on two systems I put 40mm pipes running into the sump they handle a bit more water the other ones are all 25mm. The tanks are in banks of 6 per system and each 6 tanks has a 4500lph pump. I agree it does make a difference if there horizontal. Glenn I still think his problem is the pump I think its just to big for the system he has. Link to comment Share on other sites More sharing options...
Josh Posted May 2, 2006 Share Posted May 2, 2006 I think the problem is the horizontal intakes. Take them off and see what happens. Or build a durso style stand pipe. Link to comment Share on other sites More sharing options...
Caesar Posted May 2, 2006 Share Posted May 2, 2006 Glenn I still think his problem is the pump I think its just to big for the system he has. I don't agree. I run a 10000l/hr pump on my setup and I have never encountered a problem. Possibly overfiltration but is there such a thing? This still doesn't answer why he is getting more water into his sump when it is on. It has to have something to do with his return pipes. Possibly make them 40mm diameter? Link to comment Share on other sites More sharing options...
Nigel Posted May 2, 2006 Share Posted May 2, 2006 Glenn I still think his problem is the pump I think its just to big for the system he has. I don't agree. I run a 10000l/hr pump on my setup and I have never encountered a problem. Possibly overfiltration but is there such a thing? This still doesn't answer why he is getting more water into his sump when it is on. It has to have something to do with his return pipes. Possibly make them 40mm diameter? ← I agree with you but the same thing would happen if he put a 4000lph pump as putting 40mm pipes may not be an option he would have to drain the tank and I bet the holes would be to small for 40mm pipe. thats why I say its the pump. Link to comment Share on other sites More sharing options...
Ash Posted May 2, 2006 Share Posted May 2, 2006 yes, now that he's filled us in!! a siphon ill NEVER work - BAD IDEA! two 20mm pipes are tiny, they'll struggle with a 3000ph pump. either break down the tank & get 30mm+ bulkheads, standpipes & plumbing (if the drilled holes allow it) or get a smaller pump. In the mean time you can bleed off pressure from the larger pump so it won't beat the pipes just using gravity Whatever you are making the siphon with, throw it out of the tank & forget about it, you'll never get it to work. Who told you to use a siphon like that? Worst idea ever, since ice in beer Link to comment Share on other sites More sharing options...
Caesar Posted May 2, 2006 Share Posted May 2, 2006 Hopefully this works. I have attached some pic os my sump setup with a 10000l pump. If you have a close look at the tanks I have the return pipes (in black) running from my top two tanks into my bottom two tanks then into the sump. I think the issue can be solved if the pipes are open ended running vertical. I agree with you nige about the size. This may be an issue but I would try taking the side arms of prior to drilling bigger holes. Thinking about it two 25mm return pipes should be sufficient though. Anyway hope this helps. Link to comment Share on other sites More sharing options...
Bruce Posted May 3, 2006 Author Share Posted May 3, 2006 I also agree, the pipes are way too small for the pump size. But when I am running such a big tank I want to change the filter intake not the pump. What are some other options that I have to change the way the water gets to my sump? I was thinking an overflow box? But some of you have now said that they are a bad idea? What's the problem with them? Bruce Link to comment Share on other sites More sharing options...
Ash Posted May 3, 2006 Share Posted May 3, 2006 If you can empty the tank, see if Nigel or Wayne can drill it for you. Get a 50mm hole for a 40mm bulkhead or so, as a 3rd one to go with the others. I believe enlarging the existing holes would be fraught with danger Link to comment Share on other sites More sharing options...
Bruce Posted May 3, 2006 Author Share Posted May 3, 2006 The only problem with that is that the sump may not of been designed to handle such flow. It may flood and spill over. I was thinking of getting rid of the standpipes and replacing them with an overflow of some sort. Bruce Link to comment Share on other sites More sharing options...
Ash Posted May 3, 2006 Share Posted May 3, 2006 the sump will handle it no worries - it can only flow down as fast as it's pumped up if you set them up properly. It is the time to change to a weir though if you like them, consult Wayne I'd say. Link to comment Share on other sites More sharing options...
Bruce Posted May 3, 2006 Author Share Posted May 3, 2006 I have just talked it through with my dad and he also agrees that the best option is a weir. I prefer them to those ugly standpipes anyway. How much is two holes and weirs gonna set me back? A ballpark figure? Bruce Link to comment Share on other sites More sharing options...
Ash Posted May 3, 2006 Share Posted May 3, 2006 Click on the Xtreme Aquariums banner up the top & ring them. Link to comment Share on other sites More sharing options...
Bruce Posted May 3, 2006 Author Share Posted May 3, 2006 I think it's too late now. I called the mobile no. of Wayne but no answer. I guess I would use a a pump to get the majority of the water out and then a siphon. How do I get out the last couple of mm of water? Bruce Link to comment Share on other sites More sharing options...
BaZ Posted May 3, 2006 Share Posted May 3, 2006 Soak it up with a towel Link to comment Share on other sites More sharing options...
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