When -- and how -- to close the pool

 

 

My prior strategy for timing the closing of the pool may have been a factor in the horrible experience we had when opening the pool the following Spring.  That time, it took more than a month before we could even see the bottom of the pool.  (The other major factor was probably allowing all the leaves and dirt on the pool cover to fall into the water as we removed the cover.)

Now my strategy is temperature-based:  Close the pool when the water temperature falls persistently below 65℉.  In 2017, this should've been Veteran's Day weekend.

We took the following steps and are hoping they are sufficient for our situation:

• Keep the water balanced and clean all the way until closing.
• Ideally, while the water is circulating the day before closing, drop in loading doses of Chlor-Brite, Fresh 'N Clear, Algae Control, Ultra Brite, Pool Magic+PHOSfree, and Metal Free from the closing kit that Leslie's Pool Supplies sells.
• Turn off the booster pump, remove the Polaris cleaner and replace its threaded wall port with a plug.
• Backflush and rinse the filter.
• Waste-pump the water until the level falls to the skimmer sill.  Monitor the water level very carefully towards the end of this step.
• Grab the "Gizmo" skimmer inlet plug and keep hold of it through the next step.
• Giving the system your full attention, set the pump to "Manual" at the highest RPM.  Deliberately waste water until the pump draws air.  Run over to the skimmer, screw in the Gizmo, then run back to the pump and turn it off for the season.
• Open the pump stop cocks -- two at the bottom of the main pump and one at the bottom of the booster pump.  Put them in the pump strainer and secure the lid.
• Turn the multi-valve to the "Winterize" position and open its bottom drain.
• Detach the inline chlorinator and let the trapped water drain out.
• Still in the pump house, close the just-above-ground first-intake and last-output valves.
• Remove the waste hose from the multi-valve, reel the hose in, and close up the pump house.
• Install the pool cover.

(This is an update to my earlier post, "When to close the pool".)

When to close the pool

(Note that I now consider this to be poor advice.  See my later post here.)

Seems like the week of the September Equinox is a good target time to close the pool.  This year I saw the first significant leaf fall (in someone else's yard, from a kind of tree we don't have on our property) on September 29th.

When to open the pool

Open the pool after the catkins have fallen from the trees.  This year, April 15th (tax day!) seemed to coincide nicely with the end of the Spring catkin droppings.

UPDATES:

• Clean off the pool cover before removing it so that leaves and dirt won't fall into the water and feed the algae that will develop.

Adding granular cyanuric acid to an outdoor pool

When adding large quantities of granular cyanuric acid (chlorine stabilizer), such as right after completely refilling filling the pool with tap water, take the lid off the container, keep the container upright, slowly lower the container into the pool (minimizing the amount of granules that escape the container), and use a hook with a long handle (like a hoe) to ease the container by its handle all the way to the bottom of the pool at a flat spot such as in the shallow end. Allow the container to sit with the granules inside until the crystals are all dissolved (which may take 2-7 days). Do not run the Polaris -- it can topple the container, putting granules in direct contact with the vinyl and damaging it.

This process prevents the granules from accumulating in the filter (resulting in sky-high pump pressures) or in the IntelliChlor (where they may damage the blades).  It presumes no one will be swimming in the pool until the granules are completely dissolved.

Better yet, spend the extra money to get the instant liquid salt-based chlorine stabilizer instead.

The importance of shielding outdoor gear from sunlight

Shield virtually everything from sunlight. It will all last much longer. Because water in an outdoor pool cannot be protected from UV sunlight, which quickly destroys free chlorine, the water must contain cyanuric acid (chlorine stabilizer).

D3 operating patterns

[I originally posted this to vox.com on 18 Nov 2008.]

Managing photographic exposures using ambient light involves managing a triad of sensitivity, shutter speed, and aperture.  Change the value of one element of the triad, and like the sides of a triangle, at least one of the other elements must also change, or the exposure becomes incorrect.

In the days of film, sensitivity was conceptually fixed at a particular ISO.  Thereafter, only two sides of the triangle could be adjusted.  Automation allowed one to adjust those two sides by moving their vertex.  The only choice (on a full-featured camera like the F5) was from which direction to approach the vertex:  aperture-priority or shutter-priority.  In practice, this was trivial.  I always chose aperture-priority because it's all my FE2s had.

In the world of digital photography, one can adjust sensitivity from frame to frame.  This is a great power with which comes additional conceptual responsibility.  One must develop new patterns for managing the triad.

I'm currently evaluating two different patterns of exposure management on the D3:  "P" and "M".  I'm not exploring any options that require manual ISO adjustments, because the D3's controls do not make it easy to identify the ISO button by touch alone -- especially when wearing gloves.  Whether I settle on just one pattern, or switch between the two depending on the situation, remains to be seen.

Pattern "P" is encouraged by the D3's default settings.  The disadvantage is that shutter speeds that would match (for handheld use) a zoom lens's shorter focal lengths will be less accessible:

• P: Programmed Automatic mode.  I used to get hung up on a desire to return the camera to its standard program after using a command dial to deviate from it, but I finally realized that this was pointless.  All I was deviating from was the median compromise.  Big deal.
• On every lens change, set the Auto-ISO Minimum Shutter Speed to match the lens's maximum focal length.  This is less of a hassle now that the firmware provides a better way to access frequently-changed menu options.
• Adjust the aperture-shutter vertex via one command dial.

Pattern "M" requires more intervention on every shot and may allow more image noise than necessary, but eliminates changing menu settings and makes handheld shutter speeds fully accessible no matter what the current focal length:

• Auto-ISO ON with Maximum sensitivity = Hi-2.  This provides maximum ISO flexibility.
• M: Manual mode.  This is the only mode in which the camera will loosen its death grip on ISO 200.  In all other modes, the camera would rather reduce shutter speed to below hand-held range than increase ISO (and therefore noise).  I'm willing to accept the noise if it's the difference between getting a sharp shot or a blurry one.
• Adjust aperture and shutter speed via two command dials.

Fortunately, switching between the two patterns is a simple matter of depressing the mode button and rotating a command dial.

When CSS changes don't seem to work

[I originally posted this to vox.com on 20 Aug 2008.]

Consider that the browser probably caches the CSS file(s) associated with a page.  I was stuck for quite a while before I realized that IE7 was using cached CSS instead of my just-modified CSS file.  Clear the browser's cache between tests.