anyone have any thoughts?

You might want to install a ball valve after the valves to prevent the air from damaging the diaphragm on the valve. You can also install drains on the pressure side of the valves to drain after you shut the water off to them. I would also turn your valves on and keep them in the on position so they don't build any pressure and damage them as well. Here is a link that might be useful: do_it_your_self_site

The size (ie gals) does not matter. You need enough air flow or CFM to do the job. The big units have over 100 cfm. Some recommend at least 40 cfm. I rented a 15-20 cfm unit since no body rented a 40, and it did the job just fine. My system is 3/4 poly, with no sprinkler heads - it is just a burried system to provide water at remote locations. I collected the water at the outlet of the system, and all water was out in a few minutes. Most home compressures only have about 5 cfm. It might be of interest to know how to connect the unit. I took off the standard compressure connector (screws to the hose) and the remaining piece fit just perfectly in 1/2 inch hose, which I connect to the system.

"If all the icebergs in the ocean melted, will the ocean level rise, fall, or stay the same? There has to be a scientist on here somewhere. :-)" Been there, did this for a chemistry class. It was more a density calculation, but I don't quite think they expected any of us to do the expansion coefficients at various temperatures. It depends on the ocean temperature that results as water has a density of 1.0000 at 4 degree C. Density drops above that (the water expands). It's 0.99987 with water at the freezing point, and of course, it becomes about 0.9 as ice. So the water volume resulting from the ice is actually relative to the water it's melting into--usually pretty cold, under 4C, but that's not always true (they've been spotted even into the tropics after very stormy conditions). Generally, the water, at least initially, is of greater volume than the iceberg it's coming off of. Over time, as it warms, it will be the same, but that takes some time to equalize, although the volume differential is very slight (rarely more than 0.02%). However, we cannot ignore that if we wish to be exact. For icebergs in the tropics, the water melting off could be up to three percent different. Most people will simply give the answer "it stays the same," given basic displacement, which is acceptable, given the relative addition of the small amount of water contained within free-floating icebergs at any given instant. We've just seen it's not quite so simple and water of various temperatures is actually of different densities. However, overall, there simply aren't that many icebergs, and they're already displacing water. Even with a theoretical three percent differential, which you aren't going to notice in the real world when standing on shore, we can confidently state, "The ocean level will not visibly change." Even though, in reality, it actually does rise a touch more than one might expect if one could measure accurately enough both for the density reason and for one other--gravitational attraction. I discuss that a bit below. Note: This only works for icebergs ("a large floating mass of ice detached from a glacier or ice sheet and carried out to sea"), a la "ICEBERG! RIGHT AHEAD!" Poor sods. If you mean glacial sheets, there are actually many considerations here. The sheet can be grounded, floating, or partially floating and partially grounded (Antarctica's Ross Ice Shelf exhibit all three characteristics), so the amount of rise depends. Fully grounded ones will increase ocean rise far more than floating ones, where the rise is only from the expansion of the water. ...Or so it would seem. However, the ice shelf itself contains mass. The Ross Ice Shelf is the size of France. Observed as a gravitational anomaly (and we've done so), it actually attracts water (and atmosphere) to itself, which begins to "relax" back into the ocean (and air) as it melts, increasing ocean depth just from the water flowing back as it's no longer attracted to the mass of the ice and begins to flow back into World Ocean proper. ...No, I'm not nuts. It's an amplification effect. Minor, but there, and it does have to be accounted for when you have country-sized masses of ice moving about on your home planet. If it all melted and redistributed its mass (you'd end up with a bit more of that bulge heading for the Equator due to rotational and, again, gravitational effects), you'd end up with, on average, a 230 foot ocean rise or so. give or take 30 feet or so (we're not entirely sure how much water there is and it depends on the water temperature again since warmer water expands more). But that requires an enormous amount of energy and, unlike freezing, phase changes are constant. Superwarming doesn't happen and you won't get a wave of melting, unlike supercooling and a wave of crystallization.