Sunday, September 20, 2009

What I did last summer (part 3): plumbing the water feature

The previous post described the building of the water feature but only briefly touched on the plumbing necessary to get it working. In this post I'll talk about the water feature plumbing in detail. In the next post I'll talk about the many adjustments made after we got the water running, and the related lessons learned.

As a complete newbie to the topic of garden water features I found the jumble of information about water feature plumbing very confusing. I read the literature that I mentioned previously, and talked to a lot of pond/stream owners at the 2009 Garden Railway Convention (which this year was in Colorado). Eventually I sorted out the information as follows. First, there are basically three kinds of water features: only pond; pond + stream/waterfall; and only stream/waterfall. The type you choose will determine what plumbing you need -- and some of the things you see advertised won't apply to your type of water feature.

Second, if you will have a pond you need to determine up front if you want fish and/or plants in your pond, and if you want fish do you want koi, which are more complicated to take care of. The more life you want in your pond, the more plumbing support that is required.

So, I made some decisions to help simplify the process. First, we won't have koi, as they require a deeper pond (preferrably 3 feet deep) and my pond will be only a foot deep at the maximum. Goldfish are cheaper and easier from a maintenance perspective. Second, yes we may add fish and plants in the future, but first we'll run the pond for the rest of this year without them just for the experience and to let the new mortar, etc. properly cure, as mortar and cement can apparently release chemicals that harm water life.

With that decided the plumbing requirements were somewhat simplified. First, you need to have a pump to move water from the pond to the top of the waterfall. More on that in a bit. Second, you need to protect the pump from water debris and to have some means to remove that water debris. Third, you need some kind of filter for the dirt, dust, and algae. Various things are suggested in the literature, but the biofilter concept seems the most popular. If you want fish you may have to add other mechanisms, such as UV filters, to keep the water habitable, and you'll need to monitor water chemical levels regularly, just like with a fish tank. For this year I'm not worried about any fish-related requirements, but I'll probably have to learn more about those next year.

As mentioned in the last post, Aquascape has a line of products that they sell through pond specialty stores which are perfect for the task, but extremely pricey. For about $1100 you can get a do-it-yourself kit that includes everything you need for a small pond and waterfall, although I'm told most people pay another $200 or so to upgrade the pump for more water flow. When you get one of these items like, say, the "MicroFalls", you'll pay $280 list (and I've not found any one on-line who discounts these products) and the components look like something you'd pay less than $50 for at a big box store. Alas, the big box store doesn't have anything close to an equivalent, although you could probably build something functionally similar from parts if you knew what to build and what parts to acquire and customize.

So, in the end the Aquascape do-it-yourself kit is probably a smart purchase for a lot of people in that it gets you where you want to go with minimal aggravation. At this point I own most of the items in that kit, although I took a long road to get there (some of those details will be covered in the next post).

Two things I knew I wanted were a biofilter and something that would serve as the start of the top of the waterfall. The MicroFalls is both, and was recommended in those Jack Verducci Garden Railways articles I referred to earlier. So I bought one and installed it at the top of the waterfall. This picture shows the box after it had been put in place but before leveling and attaching the hose:




This next picture shows the MicroFalls from the side, fully installed:



Installation was not hard, although the directions could be simpler. Dig a hole until the lip (water exit) of the MicroFalls is at the level you want. Then attach the hose to the lower back of the box (this probably means digging a narrow ditch for the hose, which I did), and attach a rubber liner to the front lip using the instructions. Put in the two biofilter mesh pieces, then add some lava rocks to the rock net-bag on top. At that point you're ready to have a pump push water in through the bottom hose. The water will percolate up through the filters and out the front lip. The beneficial bacteria that will clean the water will form naturally, but just in case Aquascapes has a small can of dry bacteria for $20 that you can add to your pond to speed the process along. Don't fill in the dirt around the box until you've verified that there are no leaks.

Next on my list was a pump. Pumps can be submersable or external, but most people use submersible because they are easy to locate in the pond and by doing so you deaden the pump noise. These are rated in gallons per hour (gph) and also in watts of electricity drawn. The gph rating is complicated because the official rating is measured assuming the water is pumped out directly and not moved anywhere. Vertical movement, like up a falls, cuts down on the gph tremendously, and horizontal distances also cut down, but by a factor about 1/10th of the horizontal. There are charts in books that show the degradation on gph for your given situation, but those are only estimates as different motors have different characteristics.

Finally, once you've figured all the math out you realize, if you are a newbie, that you really haven't a clue what your output gph should be for the size of stream you want. You can guess, but you don't really know.

In the end I bought a "cheap" 3600 gph, 300 watt pump at Lowe's for $200 + tax. It was the biggest they sell. The equivalent Aquascape is over twice that price.

Unfortunately, the pump didn't have a provision for a debris filter. After thinking and thinking about how to keep debris away from the pump I took a short cut and bought a $30 "pump buddy" from Aquascape that is simply a filter bag that wraps around a pump.

Then I bought two 20 foot lengths of flexible 1.5" tubing (that was the longest size our local Home Depot had) and some connectors. I connected the pump and the tubing up to the Microfalls and all was ready. This next picture shows the pump, wrapped in the "Pump Buddy" and sitting in the dry pond, and the tube leading from it to the (off camera) MicroFalls:



All was ready to start the water running. As I said earlier, this was an exciting day given how long we'd been working on this. We put a hose to the top of the stream and turned the water on:



The water began trickling down:



And down:



To the island:



And to the pond:



Yes there were a lot of photos taken that day. And video too. When the water was deep enough we turned on the pump and the MicroFalls started gushing, as shown in the last photo of the previous post. This photo shows the pond filling up after the pump was turned on:



All was well, except that the pond water seemed murky. As it turned out this would create a plumbing problem, but I'll cover that in the next post on tuning the water feature.

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