Pool Shock: Surprising for Algae Elimination


Welcome again to high school, college students! Summer time is the right time to debate algae and easy methods to take away it by stunning the pool with Calcium Hypochlorite – Ca(OCl)2.

Chlorine is a Nice Algaecide, I prefer to say. Sooner kill charges and a extra full response than utilizing algaecide or different oxidizers.

Cal Hypo is the right chlorine sort to make use of to eradicate algae blooms – highly effective and economical.

Our dialogue will concentrate on how a lot pool shock to make use of for full algae elimination, plus different recommendations on efficient pool stunning.

Preparation for Surprising

1. Clear Pool Totally. In case your pool has particles or leaves on the underside or floating on prime, this can intrude with the method. Chlorine will assault this natural matter, fairly than the algae.

If the pool is simply too darkish inexperienced to see the underside, use a Leaf Rake, or the Leaf Gulper and clear as a lot of the particles as you’ll be able to from the pool earlier than stunning the pool.

2. Decrease the pH. Cal Hypo (and actually all chlorine merchandise) have higher efficacy at a decrease pH stage. Add an acid to regulate the pH to 7.2. Verify your Alkalinity first, to ensure that it’s within the vary of 80-120 ppm, earlier than adjusting your pH stage.

3. Assess the Algae. Decide the extent of severity of this algae assault.The dose listed on a bag of shock (1 lb. per 10K gals) is admittedly only for clear and clear water, for algae, you want rather more! What’s the stage of algae in your pool?


LIGHT GREEN: Water is generally clear, with areas of seen algae.
MEDIUM GREEN: Algae in all areas, visibility low at 18-36 inches deep.
DARK GREEN: Thick algae deposits, visibility restricted to 12-18 inches deep.

Surprising for Algae Elimination

It’s a usually accepted notion that 30 ppm of chlorine residual will kill all algae. Assuming that your pool is clear, and you’ve got adjusted the pH, now you can add the granular chlorine to the pool.

Most pool shock packages will checklist instructions so as to add 1 lb. (1 bag) of shock per 10,000 gallons of pool water. Which may be effective for regular circumstances, however when you have a extreme algae assault, a triple shock is required. 1 bag will get attain 7-9 ppm, however for 30 ppm, you want 3, 4 or generally even 5+ lbs per 10,000 gallons of pool water.

“Shock it till the water turns Blue-ish”, mentioned Davy Merino, our weblog editor. “That’s what I do”. A effective approach – you do wish to add shock to the pool till the water loses the inexperienced colour, and turns a blue-ish grey colour.


Right here’s a chart that can be utilized with our Pool Shock and Tremendous Pool Shock merchandise. The numbers point out the quantity of shock, in kilos. You might want extra to see the blue colour start to return to the pool.


How a lot shock is required to attain 30 ppm will range relying on the out there chlorine share of the shock you’re utilizing. For instance, if utilizing In The Swim Tremendous Shock, it’s a 73% cal hypo shock, however HTH Shock -N-Swim is simply 45% cal hypo; so that you’d use extra – or much less, relying on the shock efficiency.


bucket-o-waterOne of the best ways to manage shock into your pool is by pouring it right into a bucket of water with no less than a pair gallons of water. Combine it to dissolve, and pour the combination across the perimeter of the pool. Bear in mind: at all times add shock to water, by no means add water to shock!

Now it’s time to attend some time. Maintain your pump and filter operating. Give the shock a superb 12 to 24 hours to work it’s magic. If the algae hasn’t cleared up after 24-48 hours, clear and brush the pool and add one other shock remedy.

When the chlorine has utterly completed working, the algae within the pool will flip a white/grey colour and can both settle to the underside of the pool or be suspended within the water. There shouldn’t be any extra inexperienced colour and the water visibility needs to be bettering. Run the filter 24/7, and backwash as wanted.

8 Ideas for Extra Efficient Algae Elimination

  1. Put away the algaecide – pool shock destroys or deactivates algaecide.
  2. Decrease the pH earlier than stunning, 7.2 – 7.4 is greatest for shock efficacy.
  3. Dilute pool shock in a bucket of water for vinyl liner swimming pools.
  4. Run the filter 24/7 till water is obvious. Backwash solely as wanted.
  5. Brush the pool vigorously, a number of occasions after stunning the pool.
  6. Don’t use a photo voltaic blanket till chlorine and pH stage are regular.
  7. If chlorine stage drops to zero inside 24 hours, Repeat the shock remedy.
  8. Enhance filtration with a pool filter cleaner or filter help like Jack’s Filter Fiber.


After just a few days, you’ll be able to vacuum up the shock mud, or brush it each day and run the pool cleaner if you happen to don’t have a strategy to manually vacuum the pool. Utilizing a Clarifier may be useful to assist pace the filtering of small particles; shock mud and useless algae.

If doable, it’s best to vacuum the useless algae to waste. You don’t wish to lure all of the useless algae in your filter. That may create a recurring algae downside. Vacuuming to Waste is difficult with a cartridge filter, however not unimaginable.

As soon as the particles is gone from the water, it’s time to brush once more with a brand new or good situation pool brush. Be sure there isn’t a residual algae left on the partitions or ground. Brush vigorously! When you really feel the ache in your shoulders and arms – you’re doing it proper!

pool brush


filter-perfectAfter a radical vacuuming and brushing, it’s a good suggestion to wash your filter as properly. When you have a DE or cartridge filter, take away the factor and soak or spray with In The Swim Cartridge Filter Cleaner, and spray away all filth and algae. Sand filters are a bit harder to get clear. You may both exchange the sand, or you should use a Sand Filter Cleaner. Pure Chemistry’s Filter Good does an important job on any filter sort, utilizing pure enzymes and citric acids.


Now your water is obvious, the partitions and ground are algae free, and your filter is cleaned of any useless algae – what’s subsequent? Check your pool water once more.

Check and modify your pool to those ranges: Free Chlorine: 1-3 ppm, pH: 7.2 – 7.6, Alkalinity: 80 – 120 ppm and Calcium Hardness: 200 – 400 ppm. Correct water steadiness in your pool is essential to sustaining clear water and staying algae free.

danger-zone-signAny time your pool drops under 1 ppm of free chlorine, you’re within the hazard zone for algae (to not point out micro organism and viruses), particularly in case your pH and Alkalinity ranges are off too! When your chlorine stage just isn’t excessive sufficient, it fails to kill natural compounds that help in algae development.

Algae feeds off of phosphates present in vegetation and virtually all different issues in the environment. When phosphates enter the water with chlorine under 1 ppm, you’re virtually certain to have an algae bloom. Typically it could actually even occur in a matter of hours!


phos-freeForestall algae with with good water steadiness and fixed chlorination. There are a whole lot of upkeep merchandise on the market to assist safeguard towards algae and preserve it from ever being a difficulty. For additional algae prevention, use weekly upkeep doses of algaecide and Pure Chemistry’s PhosFree, to remove an algae meals supply.

Algae is rather a lot simpler to stop than to take away, however upon getting it, brush the pool, decrease your pH with a pH reducer after which Tremendous Shock the pool. Vacuum and brush once more and clear the filter – that’s the simplest strategy to get your pool again to regular.


Utilizing a pool filter cleaner after a significant clean-up is a good suggestion. Relying on the age, you may additionally elect to alter the filter media, with new filter sand or a filter cartridge alternative. Within the case of Yellow Algae, Pink Algae, or White Water Mildew, filter media alternative is strongly beneficial.

Upon getting issues below management, you’ll be able to start utilizing upkeep doses of a good high quality algaecide, keep a continuing chlorine stage, a superb (low) pH stage, and function the filter for 12 hrs +/- each day.

In Sum, stunning for algae elimination requires a superb pH, a superb brush, and a Triple dose of Cal Hypo pool shock, out there in baggage and buckets, together with efficient filtration and circulation.

So now that you just’re again to a crystal clear, stunning blue swimming pool, who’s prepared for a dip?

charlie-oserkis-pool-southern-new-jerseyMaintain America Blue!


Dr. Pool



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