Saturday, May 23, 2015

Salt water pool maintenance

Pool encounter Orca vs Mallard - N. Carlson

Backyard swimming pools are now using saltwater chlorination systems (wikipedia) to provide proper chlorination for the pools.  If properly designed the system maintains adequate chlorine levels while reducing the chloramine odors.  The salt concentration is typically in the range 2700 to 3400 ppm, although it may be higher in some systems. 

From an energy use standpoint: the salt water pools only work if the pump is operating allowing the chlorine to be generated from the salt solution.  A two speed pump can be used to keep the chlorine levels up while reducing energy consumption.   The salt used in the pool must be free of additives.

Hayword pools has an excellent guide to maintain proper salt water pool chemistry.

  1. Keep salt concentrations between 2,700 and 3,400 ppm.  This concentration may vary depending on the type of system.
  2. Adjust stabalizer - cyanuric acid levels to 60 - 80 ppm for an outdoor pool -  This reduces evaporation of chlorine from the pool
  3. Alkalinity - 80 - 120 ppm - Adjust by adding sodium bicarbonate
  4. Hardness 200 - 400 ppm - adjust by adding calcium chloride
  5. pH 7.4 to 7.8  - adjust up using soda ash (sodium carbonate)  adjust down using muriatic acid (HCL)
Keeping the cover on the pool also traps heat, reduces the amount of debris in the pool and helps maintain chlorine levels 

Thursday, May 21, 2015

High Tree pollen counts in the midwest

Photo micrograph of Oak/Maple pollen spores May 8, 2015 St. Paul MN - N. Carson - click to enlarge

There may be a reason that individuals with seasonal allergy/asthma are miserable.  Chicago station WLS reported that the Highest Tree Pollen Count in History Recorded for Midwest was noted by Dr. Joseph Leija on Friday May 1, 2015.  He measured 2,000 spores per cubic meter.

The last item piqued my interest and I check an Air-o-cell sample I took on May 8, 2013.  I measured 4,800 tree pollen per cubic meter of air on the St. Paul campus of the University of Minnesota.   Most of the pollen was either maple or oak.

Monday, May 11, 2015

Archimedes Death Ray

Ship set on fire by reflected mirrors

MIT experiment suggests that Archimedes could have set fire to Roman warships using focused reflected sunlight.  The experiment did not work well when oak was used.  When they used wood similar to cedar and under the proper light conditions with enough mirrors properly focused, the boat caught fire on top of a parking ramp.  Attempts to replicated this need to incorporate plenty of safety precautions. 

 Greenpower - 9 minutes

Healthy Home Tips by Jeffrey C. May and Connie L. May

The book, Jeff May's Healthy Home Tips: A Workbook for Detecting, Diagnosing, and Eliminating Pesky Pests, Stinky Stenches, Musty Mold, and Other Aggravating Home Problems, by husband and wife Jeffrey C. Man and Connie L. May provides a good series of checklist for home inspectors, new home buyers and home owners.  The playful banter between Connie and Jeff add to the books entertainment value and also increase the comprehension for some of the more technical discussions.

Approximately half the book is devoted to mold and water damage issues.  This ratio correlates fairly well with what I encounter during home and commercial building inspections.

Fungal growth and water damage on carpet tack strip - N. Carlson