Minimum Gravity Fall

[CincySyrupPusher]

Forgive me if this has been asked before... but what is the absolute minimum for fall (not worried about natural vac, but would be nice)?

Residential setting with total mainline (1/2") distance of under 100' (more like 88-90') with laterals branching off another 30-45'.

Will be tapping a little higher on the trees with the laterals (maybe just under BH). I know I will need the 55 gal barrel below grade (some), and will be pumping into above grade IBC for larger capacity (330gal)) but would like to minimize my digging based on your suggestions.

1/4" per 10'? 1" per 10'?

Also, I have read something about this on another post, but cannot find it. What is the easiest way to tell fall (over 90') without a transit? Was thinking about getting my wire strung and in place then take a simple inclinometer and put a few º on it.

[Bentley Wood Maple]

On a 100 ft run just eyeballing should be pretty accurate. If you want more precice measure then put a clear piece of hose on either end and fill with water. Measure the water rise in each hose and take the difference. If you have 2 ft drop from hi end to lo you have more than enough slope. Don't be afraid to tap high on end trees. I probably have 30+ taps at 10-12 ft in the air to make them work on our lines, just back wheeler up to tree and stand on rear rack. Easier than a ladder

[lpakiz]

I would consider 1% to be minimum. That's 1 foot per 100 feet. Or 1 inch per hundred inches. Even then, you will have to have supports no farther apart than 25 feet. That computes out to 3 inches every 25 feet. Of course, a bit more fall is better. Use a clear tube and water to set the grade on the posts. Or a transit if you can get vision thru the trees and brush.

[madmapler]

You could also take any level 18" or longer and just sight down the top of it. Either prop it on something or have someone hold it level. Its plenty accurate.

[Snowy Pass Maple]

You could also take any level 18" or longer and just sight down the top of it. Either prop it on something or have someone hold it level. Its plenty accurate.

I also found that this worked well for us.

I also found that a handheld GPS with altimeter is reasonably useful for confirming if you really do have 10-20 feet rise over a couple hundred feet when it's not so obvious by sight. And it allows you to make cool maps of your maple woods!

[Maplesapper]

mount an old rifle scope to an 18" level....

[PerryW]

You could also take any level 18" or longer and just sight down the top of it. Either prop it on something or have someone hold it level. Its plenty accurate.

You can use a small mirror to see the bubble at the same time as you are sighting down the level. (poor man's sight level)

[jcyphert]

You can use a small mirror to see the bubble at the same time as you are sighting down the level. (poor man's sight level)

Just make sure you have the mirror adjusted correctly or you might be looking at the wrong "bubble". Ha hahahaha! just kidding!

[heus]

I tried mounting a green dot laser pointer on a 3 foot level. You could see the dot hundreds of feet away during the day. However, I was not sure how accurate this would be so I couldn't trust it.

[DrTimPerkins]

Just make sure you have the mirror adjusted correctly or you might be looking at the wrong "bubble".

Of course with the level you're looking for dips....so incorrect mirror adjustment might just result in finding one. Fixing it might be more difficult.