Does water flow up hill?

.357

.357

Member
Maybe some of you can answer my flow questions. Does water flow up hill? I know it sounds silly, but this is what I am up against. I want to move my filter system out to the garage. To do this my plan is to increase the drain off my one built in overflow to 2". I will then run this 2" drain into the wall and down under the house. This will create a drop of at least 48". The drain will need to run about 25' horizontally under the house at which point it could need to turn up as much as 16" before dumping into the filter. The overall drop will still be 32" just to the bottom of the drain. My tank is a 125H and I would like to get 1400 gph with this set up. The reason for the move is temp and humidity control. My tank is always over 80 sometimes as much as 87 and my house never gets below 65% humidity.
 
scsinet

scsinet

Active Member
A couple remarks...
First of all, water only flows uphill against gravity on Uranus (cue the laughter and applause), but in your case, you have a larger drop behind it pushing the water up, so it'll work.
I would recommend though that you use quite large pipe, and arrange it like a standpipe in the wall with the hose from your overflow stuck into it... sorta like the drain standpipes that washers hook up to. That will allow air to circulate freely in the pipe and will prevent gurgling from your overflow. Since your filter end the pipe is "sealed" by water, you need air to enter from at least one side. If you like, to reduce humidity and noise, you can stuff filter floss into the space between your overflow hose and the standpipe outlet.
Also, you should try to pitch the pipe downward at a slope of maybe 1-2" per 10 feet of pipe run, so the filter end is 2.5" - 5" lower than the tank end. This will encourage the water to flow towards the filter and will minimize stagnation in the pipes (though at 1400gph that shouldn't be a problem). Finally, at the filter end, I'd put a drain plug, allowing you to completely flush out the line in the event that gravel, detritus, etc builds up and fouls your water or impedes your flow.
Another thing you may want to consider is to put a "T" at the low point in the pipe, just before your filter, and run it to a pipe that exits the side of the house with a ball valve. This will allow you to open the valve and use the pipe as a drain into the yard, so you can siphon water directly into your pipe when doing water changes... a nice little "feature."
You are gonna need a heck of a pump to get 1400gph after a 25 foot run and what will probably be several elbows.... something to consider with what PGE charges for electricty :thinking:
 
.357

.357

Member
I could use a small air pump at the top of the overflow to make sure that I am getting air into the drain. I am planing on using as much of the flexable PVC as possible to do this. I have found that much less resistance to flow and it is easier to work with. The real questions is will the 2" drain be enough? Will the 12" of rise at the end of a 25' run slow the flow too much?
Another questions is what to use for a return, and what pump will do the job. The total rise from the bottom of the sump to the top of the tank will be less then 7'
 
scsinet

scsinet

Active Member
An air pump is not going to be sufficient, IMO. You need air to be able to move freely in and out of the pipe. That's why drains have vents going up to the roofline.
The 12" rise is going to give you a large reduction in flow. What you are basically creating is a drain line with a "belly," a low lying area of the plumbing that will restrict flow. Ergo, given that I'd size 1400GPH at 2" for a normal system, I'd use at least 3" if not 3.5.
For the pump, remember that although you only have a 7' rise, you have a 25' horizontal run that will serve to introduce drag and hence more pressure will be needed... not as much as a 25' vertical run, but you will get reduced flow. I'd run a pump with a minimum of 2000GPH at 7' head. If it's too big, you can always dial back the flow a little with a ball valve.
 
.357

.357

Member
Does the size really matter? A 3" pipe is huge. Undre the house I guess it's not really a problem but inside is a different story. Does any know what the flow capactiy of 2" My understanding is that 1" is good for 900 gph.
 
thangbom

thangbom

Active Member
water will only go uphill if there is pressure behind it or it will flor to the place of least resistance... which could mean nowhere.. with that said. it is possible for water to flow 'uphill' if the exit point is lower the the enter point ( your overflow ) if anywhere your plumbing is higher the your overflow then you will need a pump.with that said. you should make a manifold ( like a control center for pipes) with gate valves ( for more control ) with the valve on the tank/overflow side, then a union right after that. then into a single line to flow to the designated spot. imo you dont need a 'vent' oven tho you should probaly make a vent valve on the top of your manifold ( somthing like them little valves on ro di unit) anyhow i think a vent will just relieve your drain of pressure which may be be good for such a long travel.
try to use 45's or long sweep 90's to cut back on 'head loss'
try to have the manifold up as high as possible but but still lower then the lowest p0int of the overflow
make sure that the exit end is lower then the staring end.. the lower the exit end is the better..
gl hf
YzGyz
 
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