I recently did an energy audit of my house and discovered that my pool was a major energy hog. Due to the salt chlorination system we need to run the filter/chlorinator for between 2 and 10 hours a day to maintain high chlorine levels. We run it longer in summer as the chlorine gets removed by sunlight (even with stabiliser chemicals).
We use a salt-chlorinated system (common in Australia) where about 20A at 12V is passed through a special salt cell that causes chlorine gas to be made from the slightly-salty pool water. You dump a few 25kg bags of pool salt into the pool every year to provide the chlorine ions, the salt cell adds electrons to make dissolved chlorine. If you keep the chlorine levels high enough, it kills the algae that would other wise make your pool bright green after about a week.
I attached my power meter to the pump/chlorinator and measured 860W (200W for the chlorinator cell, 660W for the filter pump). Based on an average run-time of 6 hours/day that’s over 5 kW-hrs a day or around $300/year at my current tariffs. Added to this is a new salt-cell every 3 years (at $300 each) plus a legion of algicides, stabilisers, and other exotic potions from the pool shop. All up I would estimate around $700/year, plus maybe $150 for every “green pool event” which occurs if (well, when, actually) we are not diligent.
But it’s the 5kW-hrs a day that really bugs me. You see I want to install a PV solar array for my house that will generate perhaps 9 kW-hr/day total. No way I want to use a good chunk of that power on a pool we hardly use. That sort of energy waste is just so 20th century! To be honest I would be happy to cover the top of the pool and turn it into a 60,000 litre rainwater tank, but on a good day it does look kinda nice:
So I started looking around for alternatives to chlorine. Some Googling brought me to the Floatron. This gadget uses a completely different principle to zap algae – ionisation. Rather than using chlorine it injects small amounts of copper ions into the water, which apparently kills algae but doesn’t bother us much. The cool thing is that copper ions last for 3 weeks, regardless of how hot it is. This also means that the copper ionisation process can be solar powered, as just a minute amount of electricity is required.
The testimonials looked good, so I tracked down the Australian distributor and bought one. It wasn’t cheap, about $450 delivered. There was much “wailing a gnashing of teeth” over the price by my wife, sick of spending money on that (add choice Italian swear word) POOL, but I convinced her that if it worked it would pay for itself quickly. I was a little bit nervous about the purchase, I mean, if it’s that good why can’t I buy one in my pool shop? More on that question later.
So I threw it in the pool about 2 months ago and duly followed the instructions. As the copper levels built up I reduced the chlorine by lowering the time we ran the pool filter/chlorinator each day. So far so good, the pool is healthy and my energy use is way down. After 2 months I now feel I know how to manage the pool using the Floatrons ionisation method.
With the Floatron you still need trace amounts of chlorine (about 20% of what is normally required). As well as killing algae chlorine also acts to keep the water clear. Initially, in my rush to reduce energy consumption I reduced the filter/chlorinator run time to just 1 hour a day. However the pool water tended to be a little blue-green and cloudy (e.g. objects on the bottom of the deep end were fuzzy). Any sort of green in normally a sign of algae breeding madly, so there was a moment of panic!
However I think it was more a case of dissolved (but benign) particles in the water rather than a run-away algae event. I upped the filter/chlorinator run time to 2 hours a day and after about 3 days: clear blue water, about as good as I have ever seen our pool. The chlorine level was still very low (maybe 0.3ppm, way lower than 1.5ppm required normally), but the water was clear. Normally at this time of year (November) we would be running the filter/chlorinator 6-8 hours/day.
Now this management of the residual chlorine level gives me an added level of control. I could drop back to 1 hr/day on the pump if I wanted to. I would get cloudy water but who cares if I am not using it? No risk of an algae attack so I can rest easy. Then, if we have an imminent party or kid invasion coming up, I just up the run time to 2 hours a day to get clear water. I like having this choice – previously I was forced to keep the run time (and expense) up, waste power and effort, as if my pool ever went green it would take me 2 weeks and $150 of algicide/shock treatment to fix it.
This got me thinking about the whole salt chlorination system and business model, and the reasons why using ionisation (rather than chlorination) isn’t that common. I mean the Floatron has been around for 15 years, so why aren’t we all using it?
Think about a salt chlorinated pool. If something goes wrong, e.g. the salt cell gets blocked or you flick a switch the wrong way and you don’t notice for a few days you get a green pool quickly, as the chlorine level drops immediately, especially in hot weather.
The warmer it gets, the more quickly the the chlorine breaks down, so the more you need to run your pump/filter/chlorinator. We varied between between 3 and 10 hours/day over the year, more in summer if the chlorine levels were low, or if the salt cell was nearing the end of its life. Plus you have the expense of a $300 salt cell every few years (we have gone through 2 in 7 years). Being chemically-challenged and slightly lazy we always end up with 1 or 2 “green pool” events a year. This means a trip down to the pool shop, $150 worth of shock treatments, algicides, and much stress and head scratching while we work out what we did wrong this time.
There are other benefits apart from reduced energy costs. Running the filter and chlorinator for a only a few hours a day reduces lots of wear and tear on expensive equipment, perhaps as much as 80%. Using ionisation to kill bugs means less risk of the pool quickly spinning out of control and going green as the copper ions last 3 weeks compared to chlorine in summer that lasts just a few hours. Now all we really need to buy is a few litres of acid a month to keep the PH between 7.2 and 7.8.
So the Floatron is a great thing for a pool owner but a very bad thing for a Pool Shop owner. Just about every dollar we spend at the pool shop is related to chlorine in some way, for example pool salt, algicide, new salt-cell, stabiliser. It even saves on filter sand and kreepy-krawly (automatic pool vacuum) replacement parts as they wear in proportion to filter use. This works against the Floatron – what pool shop would stock a “product of death” to their other lines?
I have two minor criticisms of the Floatron. Despite paying for itself quickly I think at AUD$450 here in Australia it is too expensive. I would suggest something closer to the US price of US$270. Having said that I would happily buy another one tomorrow at AUD$450, just my gut feels says it should be a little cheaper. The printed manual is well written and tells you everything you need to know but is written entirely in UPPER CASE. THIS MAKES IT HARD TO READ GUYS (note however the on-line manual from the Floatron web site makes good use of lower case).
So in conclusion I think the Floatron is a great product, and ionisation is a fantastic way of maintaining a pool compared to chlorination. I figure with energy prices rising the energy costs of luxuries like pools need more attention. Ionisation is low on energy, low on chemicals, less chance of algae, less irritants, and less visits to the Pool Shop!
Low Energy Pool – How I used an old salt cell and the Floatron to reduce my pool energy consumption by 75%!