Category: Pool

Next year’s pool project

lpaulriddle

I’m already thinking about next year’s pool project, and I haven’t even started this year’s yet…

For next year, I’m considering adding an automatic chlorine feed using a chemical metering pump, similar to the setup described here. The main goals of the project would be:

  • Save work;
  • Save money on chlorine by matching the supply more closely with the demand;
  • Provide a continuous feed of sanitizer, thereby eliminating the need for cyanuric acid in the pool.

If I go ahead with this, I’ll probably also move the pool’s electrical controls indoors, which I’ve always wanted to do for convenience more than anything else. I’d also need to run a dedicated 110VAC circuit to power the metering pump, so while I’m at it, I’ll install a convenience outlet near the pool equipment. Right now, I only have 220VAC there.

The metering pump can be had from Grainger for around $300, but I’m watching eBay to see if I can get a new one cheaper.

I’ll add random notes to this entry as I think about this one.

Pool still covered

lpaulriddle

Yesterday was supposed to be the big pool-uncovering day, but it didn’t happen. The original plan was to open it early so I could get my coping project underway. But, yesterday it occurred to me that I could get started with the cover still on, and just pull the cover back to expose whatever area I happen to be working on. At that point it became a no-brainer: Leave the cover on for now and avoid the hassle of keeping the pool clean in late May when no one is using it.

I already had my help on the way over, so instead of uncovering the pool, we tackled the time-consuming job of scraping the old caulk out of the coping expansion joint. This was fairly easy to do with box-cutter type utility knives and plenty of sharp blades. However, on the decking side, it left a bit of residue because of the roughness of the concrete. I may try wirebrushing this area to get the last bit of caulk out.

Next up is to rent the big concrete saw and cut a true expansion joint (removing the caulk revealed that, as I expected, the joint is non-true around the entire perimeter of the pool). My current plan is to take a day off work and do it the week after Memorial Day. I’d like to get it done before my Vancouver trip; otherwise it’ll have to wait until June 10 at the earliest. Come to think of it, I suppose there’s nothing stopping me from doing it this week, either.. To deal with the dust, I’ll try duct-taping a tarp to the coping edge. With the cover still on, it’ll support the tarp and keep it from submerging. It might work.

I did my first water test yesterday, and surprisingly the numbers weren’t too bad: Free Cl 1.4, Combined Cl 0.2, pH 7.7, Alk 80, Hardness 170, CYA under 30. Water temperature was 63°. I’ll probably add some chlorine today.

Saturday’s Hijinks

lpaulriddle

Another fun Saturday around the house…

First up: The security system. I finally got around to relocating the wireless receiver to try to get better performance out of our new keyfobs. At the same time, I installed the status transmitter module so the keyfobs can receive status information. So far, things look good. the status transmitter seems to work fine, and there seem to be no issues with the window transmitter in the master bathroom. I had some concerns that this one would have problems because of the distance from the receiver. But, it works fine. Next up.. we’ll see how things work like this for a week or so, and if everything looks good, I’ll clean up the wiring, reattach the sirens, replace the battery and stick a fork in this one.

Next up: The pool. With t-minus one week until we uncover it, I decided I should take a look at it. I’ve had other stuff keeping me busy, so I’ve kinda neglected it for the past month or so. As I feared, it’s a nice green swamp. Anyways, to get a start on cleaning it up, I started the pump and siphoned in 5 gallons of 12% hypochlorite. We’ll see how it looks tomorrow.

[More:]

This year, rather than adding chlorine through the skimmer, I think I’ll pour (or siphon) it into the shallow end in front of a return jet. That should disperse it pretty efficiently, and it should also be easier on the pump and filter. Siphoning is a little slower than pouring the stuff in directly, but it avoids splashing, which is a big plus.

The fun never ends..

Followup 5/15.. the 5 gallons of chlorine cleared it right up and left a chlorine residual, but the pH is high now (8.2). Dunno what the alkalinity is, but I’m sure it’s low. Not sure which I should adjust first.

A bit of everything today

lpaulriddle

I skipped work today so I could ferry the clan around on various errands, and seized the opportunity to knock a few odd things off the to-do list.

First off, I paid my first visit to Namco, my favorite place to get pool supplies. The prices have gone up this year, which comes as absolutely no surprise to me. But, they’re still pretty much the cheapest place around for chemicals, particularly after late August when they blow everything out at half price (which really drives home how high the dealer markup is on pool chemicals). I bought a couple 5-gallon jugs of liquid chlorine, which is basically sodium hypochlorite (household bleach) at about twice the strength of grocery store bleach. Namco has this stuff at $13 for 5 gallons, plus a $6 deposit for the jug. That’s a decent price, and it makes me wonder how much of a premium I’d pay to use this stuff instead of calcium hypochlorite for daily chlorination. The main advantage of cal-hypo is its shelf life: I can buy it at half price late in the season, and it’ll still be just as potent the following spring. Its drawback is inconvenience. To avoid clouding the pool water, you need to dissolve the cal-hypo in a pail of water, then pour it off. Then you have a lot of sediment left over that you have to get rid of. The liquid chlorine is much more convenient, but its shelf life is shorter, so I’d need to buy it at full price during the season. The challenge here is to figure out the true effectiveness of the cal-hypo vs the liquid stuff, then see how much of a premium I’d pay for the liquid stuff, and determine if the convenience is worth the price difference. I love doing this kinda stuff, so you can be sure I’ll tackle that soon..

In other news, we got our vegetable garden planted. To keep the critters at bay, we strung chicken wire around the garden and hung some old CDs above it. The theory is that the CDs will blow around and flash as they catch the light, which discourages birds. We’ll see how it does this year. I guess the next step would be to add lawn edging to prevent moles/groundhogs/etc.

… and finally, I made a stab at speeding my wife’s anemic Windows XP box up a bit. Basically I went into the Microsoft System Configuration utility (Start Menu -> Run -> enter msconfig), went to the “startup” tab, and disabled a whole bunch of unnecessary kruft that the OS was starting up at boot time. It’s amazing the amount of junk that accumulates there over time.. Quicktime crap, Adobe crap, crap from some kid’s software we installed, crap from Dell, crap from the stupid stuff that Dell pre-installs on the computer, AOL crap, the list goes on and on. After I turned a bunch of stuff off, I rebooted and the machine seemed a good deal snappier. I guess we’ll see how it goes from here.

Started the Pool Pump

lpaulriddle

After a winter of freedom from the big money-sucking hole in the back yard, I bit the bullet and fired up the pool pump today. Now, in the Mid-Atlantic, swimming season runs from roughly the beginning of June through Labor Day. If you’re lucky, you’ll get a couple extra weeks on either end, but for the most part, that’s what you get. For the past few years, my routine has been to start the equipment up around now, and uncover the pool around Memorial Day. I’ve found that starting the equipment early saves work, because it allows me to chlorinate the water before it gets too warm and algae starts taking hold. And with pools, anything that saves work is a bonus.

Anyways, the pump primed right up using the main drain for suction. The water level is still too low to use the skimmers. And the water temperature is (drumroll please) a balmy 56°F. Another 25 degrees and we’ll be swimming.

Now I need to start thinking about my spring pool project, repairing some loose coping and recaulking the expansion joint between the pool and the deck.

Two-Speed pool pump motor: Worth it?

lpaulriddle

With electricity prices set to skyrocket in the Baltimore area this summer, I’m once again looking at ways to cut down on our consumption. And in the summer, one of our biggest consumers is the pool pump. I’ve read that a two-speed pool pump motor can cut down quite a bit on energy usage. A standard swimming pool pump runs at 3450 RPM. A two-speed pump can also run at half speed, or 1725 RPM. The interesting thing is, although it’s running at 50% of normal speed, a typical model draws less than half (about 30%) of the current that it would draw running at full speed. So in theory, you could run the pump at half speed for twice the length of a normal-speed run cycle, do the same amount of work, and use less power. Now, this might be wrong. I’m not well-versed enough in fluid dynamics to say whether, for instance, 10 hours at 1725 RPM would turn over the same amount of water as 5 hours at 3450 RPM. But, for the sake of argument, let’s assume it would. Running at low speed would certainly consume less power, and longer pump run cycles are good for the pool water because they keep it from stagnating (I’ve also heard anecdotal reports that sand filters “work better” with lower flow rates — take that for what it’s worth). Of course, that’s only one side of the story. There are also some caveats..

  1. I can’t run the pump on low speed 100% of the time. I have a pressure-side pool cleaner (Polaris) with a booster pump, and I’d need to run at full speed while the cleaner was on (3 hours a day, 3 days a week or so). And, I’ll want to run on full speed for 3 hours or so after adding chemicals, to get them distributed as quickly as possible. Any time the pump is on high speed, it cuts into my potential savings.
  2. The pump motors I’ve looked at all consume somewhat more current (1 amp or so on models I’ve looked at) on high speed, than equivalent single-speed motors. Not quite sure why this is, but it seems to be a fact of life.
  3. Initial cost for a two-speed setup is high, even assuming I’m only replacing the motor and not the entire pump. The pump would need special wiring, and a new timer/control to control high vs low speed operation. Plus, I’d need a new shaft seal. I’m probably looking somewhere in the $350-$400 range when all is said and done.

A couple years back I made a spreadsheet to estimate potential savings using a two-speed pump, and concluded that the payback period was too long to justify the initial effort and expense, given what I was paying for electricity at the time. However, with the pending rate hike, it’s probably worthwhile to crunch those numbers again..