How to Clean a Green and Cloudy Pool With a Filter. Using a Flocking Agent
Cleaning a green pool
This article is related to my "How to turn your pool from green to clean" article and was designed to illustrate with photos of how to turn a green pool around in 24 hours. All photos are click-able for viewing large images.
I received a service call for a green pool clean up. When I first arrived, of course, the pool was green (Fig.1). There were two ways I could have addressed this. The first being vacuuming the pool to waste, the second being adding chemicals immediately. I chose to add the chemicals since this particular filtration system was equipped with a good working D.E. filter, which are by far the best in terms of capturing the smallest of particles, including algae. IF this had been a cartridge or sand filter, most everything vacuumed would have blown right back into the pool. This can only be done with a D.E. filter system. Had I chose to vacuum to waste, the results of the pool clean up would have still been the same except some water would need to be added to the pool afterward since it's being pumped out while vacuuming.
When I tested the water the P.H. was around 7.2. That is a little low for pool water but perfect since I was going to add shock. Because this particular pool was a bit larger than most residential pools, I've added approximately 7 pounds of granular chlorine or calcium hypo-chloride(shock). Within 5 minutes the water begins to turn(Fig.2)
Using a Flocking Agent
Flocculation is a process in which a chemical, or "Flocking Agent" is added to pool water that is green. Most commonly known as "Drop-Out" or "Drop Down", I use this normally after brushing down a pool that has algae. In turn, the brushing causes the pool water to become pretty nasty and is very difficult to filter out. The flocking agent allows the particles to bind together which makes them heavier and will then sink to the bottom of the pool. After it sinks, it will then be vacuumed to waste (by-passing the filter and vacuuming straight out to the yard/street etc..)
Cleaning the filter and letting the pump run
I'm going to add 4 scoops of D.E. powder to coat the filter grids. This is added directly through the skimmer with the pump running. (Fig.5) Now the the timer needs to be set to run continuously until I come back the next day. In Fig.6 you will see that on the Intermatic timer, I am removing the "off" trip lever. This will allow the pump to run until it is shut off manually.
24 hours later
After 24 hours I've returned. In Fig.7 you can see that the pool has cleared. What remains is some stubborn areas, mostly on the walls. On the bottom is dead algae and some shock dust which will need to be vacuumed. Again, this can only be vacuumed through the filter if a D.E. filter is being used, otherwise it needs to be vacuumed to waste. I again chose to vacuum using the filter instead of going to waste since this is a D.E. filter. Take note in Fig.8 that I am also pulling the vacuum head up to vacuum the remaining "green" off the walls. It's important to get as much of this out as possible.
After the pool has been vacuumed, I again backwashed the filter. I brushed what was left of any green areas that I couldn't reach with the vacuum such as along the tile line, steps, etc.. Chemicals were pretty well in balance other than the chlorine still being a little elevated. Fig.9 and Fig 10 is the finished result after 24 hours.