AlphaMare101 said:
The sand wasn't too bad. <snip>
Next we let the water run in the filter until the water coming out over the top was clear & clean. I then smoothed the sand, removed the plastic bag & my husband reassembled the filter & T-15 cell.
The whole process only took about 45min, with about 1/2 of that time just letting the water run into the filter. No bad chunks of gunk, but a lot of cloudy water, a good bit of what appeared to be dead algae, a little grass, & few tiny bugs flowed out.
Sounds like you got quite a bit of gunk out of the filter. See what backwashing misses? It's crazy!!
Was it clumped, or slimy at all, if so, did that go away?
AlphaMare101 said:
The sand was changed 5 years ago, which won't be done again until we have to replace the laterals. I can't believe we paid to have the sand changed out at least every 5 years for the past 20 years, & only one of those times was due to broken laterals!
I love TFP!! :-D
Yeah, me too!!
HAHA, yeah! Sand never wears out, despite what the "professionals" think. It's more like a proffit scheme than anything else, honestly, many seem to truly believe that it does "wear out". It just sits in there, compacted, like a cake. How can that wear out??
The only time it moves around is on a backwash, that's not enough to "round it off" through tumbling.
With proper water balance & sanitation, your sand will either outlast the filter, or the pool, or both.
How did you end up with broken laterals? One way to avoid that is to use a layer of pea gravel on the bottom where the laterals are. It creates a barrier between the sand & laterals, reducing pressure on them and eliminating clogging of the sand in the the lateral grids, where the sand normally gets
pushed into the grids and gets stuck over time.
Some argue it, but the sand sitting on top of the layer of gravel only travels down so far into the gravel bed before it backs up and clogs, stopping any further sand from traveling through the gravel & reaching the laterals.
This is what they do in waste treatment plants, among other "tweaks", as well as very large swimming pools.
It prolongs lateral life, aids in more thorough backwashing and increases flow rate during regular filtration mode.
The following aren't necessarily things you have to fix, just things I thought I should point out.
Your sand filter is considerably below the recommended size for your pool. Your filter is nearly 2.4x smaller than the recommended size for your pool.
From our pump & hydraulics expert's post:
Hydraulics 101
Cartridge & DE sizes should be doubled, sand is correct.
You'll see that for your size pool of 40k gal, it is recommended to have a 7.4SQft sand filter, your current filter in your sig is 3.14SQft.
This doesn't mean it won't filter, it just takes longer to do so. IE. The filter can't trap as much junk for any given amount of water that flows through it at any one given time and it just simply has to be backwashed more often.
The flow rate is what dictates the former and is a bit complicated. It's mostly the later, having to backwash more often.
Also, if your pump motor is not a 2-speed motor, you can save boatloads of electricity by switching to one. Forget variable speed motors, unless your electricity rates are sky high, or your pool setup is highly complex. Read, lots of toys like; spa, fountains, suction side cleaners, etc... Then you won't benefit from one of those, as those things aside, they otherwise never pay for themselves.
By running a 2-speed motor on low speed, you move half the water for 1/3 the electrical consumption. See how that saves money?
Usually replacing a perfectly good pump, and/or motor with a more energy efficient 2-speed design isn't advised unless it's just really old and starting to show signs of failure, or your electric rates and particular pool warrant it.
Mark (mas985) has some pump efficiency charts at the end of his 2nd post on that page, as well as an energy cost calculation spreadsheet in his 3rd post on that page.
That is if you really want to get into the calculations on energy consumption and such. Warning... it'll likely make your head hurt!!
Just things to place in the pipe for when you're planning to do upgrades, or things start to fail, etc....
Also, take a look at this short article that'll help you save even more money....
FOR FREE!!
Who doesn't like free, right?
pool-school/pump_run_time
Since most people run their pumps waaayyy waaaaayyyy too long, this can really take a chunk out of ye' olde' electric bill each month.
