head feet question (topoff)

[cmacld]

so i am currently putting together my auto top off /water change system. I have decieded to put my system in the garage as i dont have a basement. I have two lines running from the garage to my living room, i supplying fresh ro water, the other supplying fresh saltwater in the case of a water change. For the most part it is a downhill jeorney for the water(roughly 20'), until the last 3 feet to the tank it is an uphill push. I am planning on using mag 5s to push the water. I was originally going to use 1/4" OD tubing for the sends. My question is.....what are you guys using for your tubing size and what type of pump. also im using float switches for the top off, would anyone see any problems using a mag 5 or 7 with a float switch? Any input would be greatly appriciated. I would love to finish this project ASAP. Cheers

 

[Qwiv]

I would use 3/8"tubing and an aqualifter for the top-off 1/4" might work, but it is recommended to use 3/8" for any signifigant length. Use the largest hose/pipe you can fit for waterchange and whatever the best pump you can come up with for the water change.

 

[CoolUsername]

I'm reading between the lines that:

1) There are two tanks of water that are not under pressure that you want to pump from.
2) The opening at delivery side of the tubing is lower in elevation than the tank bottom (source).
3) That the tubing is around 20' long and varies in elevation throughout the run.

I don't see any problems with this setup in terms of head. The tubing is a little small but will work.

If you are using a reed type float switch you will need a relay to switch your pump on and off. To power the relay you will need another power source. An old AC/DC adapter 9-12v would work fine for this.

For safety and pump on/off cycling reduction you might consider putting the pump on a timer in series with the relay AC input. Set it to only go on for maybe 15 min twice a day.

This way you have a measure of safety in terms of how much water would be delivered in case of float switch failure. And it will significantly reduce the on off switching to the pump as the water level fluctuates. The top off pump would really only go on twice a day and then fill till the float switch is happy.

 

[Pbrown3701]

if it is a 20 foot drop to the bottom of the tank and then only a 3 foot jump up to the tank, you should have almost 17 Feet of head pressure helping you (minus the head loss from the length of pipe).

OR are you saying it is slightly downhill and 20 feet long to the tank?

If the latter and if the pipe is relatively straight, then you are probablly working with about 6-8 feet of head. I think any normal small pump can handle that. It doesn't matter what your flowrate is since you are just doing and ATO, right?

I use an Aquamedic peristalltic pump for mine and run it through a DIY Nelson reactor on its way. Best addition I have ever made to my tank.

 

[cmacld]

thanks for the imput. Greatly appriciated. i think that i will beef up the water change lines to something a little bigger, maybe even half inch, just to make the flow rate greater, Quicker waterchange as for the pumps, i have a few mags laying around that i think i will implement, untill i need them somewhere else. thanks, ill post with the finished results! Cheers