First you have a static head of 5' and then you have to add the dynamic head. To calculate the dynamic head you need a friction loss chart. Here is a link to a very good one "http://www.performancepropumps.com/PDF_Files/FrictionLossChart.pdf". You need to have some idea how much flow you want and then every fitting that you will be using from the time the water leaves the pump until it flows out over the weir. If this is too complicated to calculate if you could list all the fittings and the amount of pipe and flow you want I can calculate the head pressure. Mike

I would not want any snails in my ponds anyway. They can overpopulate and also can carry disease from pond to pond. But if you do like snails, I can see where a small dose of salt may be harmful to some species. I personally have not found that to be a problem. Back in my water gardening days (before I gave up plants to concentrate on large koi), I always sterilized plants prior to adding them to my pond and salt was not effective against those pesky snails that tried to sneak in on plants. I had to use alum to eradicate the snails.

There are several sites that help you determine the volume of your pond. Just do a search on your browser for pond volume calculator. You should leave a de-icer on all the time since it works on a thermostat. It only uses electricity when it comes on so operating costs are minimal unless you are in the arctic circle. Since it is not attempting to raise the level of all the water all the time the cost would be far less than your heater. The area it melts or keeps from freezing is usually only a sliver, maybe a quarter of an inch, around the de-icer. It stays on the surface rather than sinking like your heater. In Pennsylvania it is unlikely you would have a problem if you plugged it in before the ice actually formed. In zone 5 I have never had the ice to be more than 6 inches and that was in sub zero cold. There are several on the market and readily available online. Cost is pretty variable. I can't judge brands simply because I have not needed to buy that many. One I purchased at a feed store 20 years ago in northern Wisconsin and the one I have now that I have not needed, I got at Menards year end sale. I have seen them at Tractor Supply, Fleet Farm and various pond shops. If I remember correctly they are more expensive than the heaters since they require the thermostat. If you don't want to spend that much you can make your own. I did that the first few years after I dug this pond. I used a refrigerator or rough duty lightbulb, the necessary wiring and a Roughtote storage box with a hole in the bottom and a float or raft made from some scrap Styrofoam board. There are plans somewhere using a search if you are curious. It cost about $10.00 with the scraps and odds and ends I had on hand. A piece of cheesecloth stretched over the hole keeps the bulb from shattering or if it does,keeps the glass out of the water. I used Great Stuff as an adhesive. The only problem was it was ugly! On the otherhand, if you use a bubbler, a de-icer isn't likely to be needed at all. My bubbler and 2 airstones go all year long for very low cost and effort. drh1, Professor David, makes an excellent case for a bubbler by itself to zone 4. The entire very excellent thread is linked below and gives more info than I can give in this post but this is his argument. "Posted by drh1 z4 VT (My Page) on Fri, Aug 20, 10 at 17:55 Hi Jenny, First, the more important questions: Nope, leaf peeper season hasn't started yet! That's usually the end of September - first week in October (for the Champlain Valley). Already many motels and Hotels are booked solid. Shoveling snow?? When one is retired it is irrelevant. You get up, you look out, you say "oh, it snowed last night; looks like 18". Isn't it pretty". You have another cup of tea/coffee; go back to bed or not. Wait until Spring to shovel out. Not-a-problem! Now to your questions: First let's deal with some heresy: a hole in your ice DOES NOT MATTER! Gasp! WHAT DID HE SAY??? Nope, it's all about providing a surface for gas exchange. IF... you're using a heater, a light bulb, stock tank heater, etc. then it IS about keeping a hole open since that is the only surface over which the gas exchange can take place. However, with an aerator the gas exchange surface is in the bubbles...NOT in the hole that may or may not be in the ice. All that air you pump in there has to go somewhere otherwise you'd have the equivalent of one of those air-hockey games only with an "ice puck" floating on an air cushion! But that doesn't happen...the air finds a way out - through a crack, through the edges, though a hole. So if it "domes over"...so what? The air is STILL finding a way out. And because you are pumping air in it is the aggregate surface area of all those bubbles that is providing the surface area for gas exchange...and it is HUGE! With a stocktank heater in our neighborhood with our winters you might get a few square feet for a hole although at -20°F you might find it disappears! But the aeration approach continues to put out 10's of square feet of surface area every minute!!! As a result not only will you keep more than enough oxygen in there (not really that much of a problem given that the metabolisms for the fish are almost non-existent as well as the microbes involved in consuming organics - and oxygen - aren't doing too much...but still not exactly zero!) but you will be stripping out ammonia and carbon dioxide and other gases you wouldn't want trapped under the ice. This is the real benefit of the approach to using aeration. As to the plastic tent? Not sure it does too much although it does allow me to see the hole for an extra couple of months. But I've had it get ice inside, even an inch or so ABOVE the water level... but still not really relevant as long as the aerator/bubbler is doing it's thing. Note the ice auger in one picture...I went out to check one fine February day (think high of -10°F!). Couldn't really see a hole in the ice under the teepee. Drilled a hole and looked...yep, everything was working fine. But the ice melted out under the teepee more about a month before it melted out of the pond so there is some solar benefit. The real purpose of the floating thing is to hold the aerator above the bottom of the pond. As to adding a stock tank heater on the coldest days?? I wouldn't bother. If you lived in zone 6 or 7 you might have some impact on the temperature in or around the heater but in my zone (and I suspect yours) adding even a 2500 watt heater is akin to performing a particular bodily function into the wind! Yes, it probably will melt out a hole, but once the heater is down near the bottom of the pond with an outside temperature of say -15° or -25°F I suspect there will be no measurable impact on water temperature. Having a heater on hand, however, does provide a way to work on thawing out a line if it develops an ice plug. I don't own a heater since, as mentioned above, I use other approaches for that problem. Like I said.. it works for me and as posted in the URL above it works for other folks as well. The problem is to understand that you are not really trying to HEAT the water to some acceptable limit but rather maintain a surface area open for gas exchange. I like cheap. I like what works...and so far, over several years, it has worked for me. The biggest factor will be whether your pond depth and volume will provide the heat transfer necessary to keep a water layer below the ice, i.e., making sure the whole (no pun intended!) thing doesn't freeze up! ---David" I definitely recommend you read the entire discussion. Anything David or Horton write is pure gold and it should reassure you. Here is a link that might be useful: Complete discussion on ice holes for ponds

Arrowhead Alpinus mentioned something else about the Picea abies 'Millcreek Broom': PICEA GLAUCA 'MILLSTREAM BROOM'. To tell the truth I got this just for the name, presumably it goes back to Linc Foster. It.s an erect dwarf plant that is a pincushion of stiff needled fox tailed shoots each topped by a prominent bud giving the general impression of a dwarf Picea abies.