Sand in the pool

jetola

Member
Apr 27, 2020
16
Denmark
Hi all,
Just registered here, as i have some questions. First of all, bought my new house with a pool 6 months ago - so im new as a pool-owner.

Specs on my pool:
Oval shape, 8*4 meters
34.000 liters
Outdoor
My sandfilter is a Sevilla 600

I dont know when the sand was replaced last, as i only have had the house for 6 months

First 1)
I get some sand in my pool and im not sure why. I have cleaned it properly and the filter has been running. I have vacumed the bottom with a robot-vacuum cleaner so in the evening the water is all crystal clear, and the pool totally clean. In the morning (my pump runs from 22:00-06:00 every day) there is sand in the pool. So - i can only assume it comes from the sand-filter. I have done a thorough backwash (5min) and afterwards a 20 sec Rinse - but still - sand i the pool every morning after the pump has run. I have read elsewhere, it could be the "lateral"-tubes in the filter that needs changing.

Questions:
1) Is there anything else i could try ?
2) Is a 20 sec rinse after backwash enough ?
3) Could it be the sand that needs changeing ?
4) If it is the "lateral" tubes - does it pay-off to get them fixed, or should i get a new filter all together ?

Thx for your time :)
/Jesper
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Hello Jesper and welcome to TFP! :wave: For your questions, I would recommend the following:
1 - Not that I can think of. As long as you are sure it is sand (feels gritty).
2 - You might try just a little longer to see if that helps. 30-40 seconds AFTER the sight glass is clear.
3 - I doubt it. Sand doesn't just go bad.
4 - If a lateral cracks, gets separated from the hub (knuckle), or the center standpipe develops a crack, generally you can replace those items. Which parts are available depends on your model filter, but generally pool owners replace those parts if they become defective.

Hope that helps address your questions. Thanks for posting.
 

jetola

Member
Apr 27, 2020
16
Denmark
Hi Texas,
Thanks for your answer. My thought was also that sand does not grow bad. I was just told that i should replace the sand every 2-3 years - why is that ?... if it does not go bad ?
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
I was just told that i should replace the sand every 2-3 years - why is that ?... if it does not go bad ?
That's just a myth. Some people just go with what they were told by a friend or local pool store. But sand in general, which has been in existence for thousands of years, doesn't just go bad or loose it's ability to filter. It does however get dirty, compacted, and may develop channels within the filter vessel. The deep clean process helps to correct those issues and rejuvenate the sand for another season.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
34,475
Sebring, Florida
Welcome to the forum:wave:

Be positive what you see at the bottom of the pool is sand. Probably 90% of the time it is dead algae.

Can you pick it up between your thumb and forefinger and it feels gritty? If not, it is dead algae.
 

jetola

Member
Apr 27, 2020
16
Denmark
Welcome to the forum:wave:

Be positive what you see at the bottom of the pool is sand. Probably 90% of the time it is dead algae.

Can you pick it up between your thumb and forefinger and it feels gritty? If not, it is dead algae.
Hi Duraleigh,
Now i tried picking it up with a little container on a pole, and it is in fact not gritty at all. I just assumed it was sand, as it looked like that - sorry. Its like fine fine powder that disolves into a little cloud in the water when I try picking it up. So, then i should assume its dead algae, which i guess is fine ? I have attached a picture here, where you can hopefully see the small "dots" on the bottom. I guess this is OK then ? - nothing wrong with my filter, just a normal day's dead algae ?

Thanks for all your input - it really helps a lot. :) IMG_0615.jpg
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jesper, if it is algae (dead or alive), we tend to get more cautious. Dead algae usually looks more grey or even white. If it's got color to it, then it's probably still living algae. In your area, water treatment, testing, and availability of chemicals may be different than here in the states. But here when we see algae, we use a SLAM Process to get rid of it completely. We also use a test kit (like a TF-100 or Taylor K-2006C) that is capable of testing FC at higher levels during that SLAM Process. Not sure if you are able to perform such actions with your products, but I wanted you to know about it to be sure. If you have any questions about the SLAM Process or Test Kits Compared, please let us know.
 

jetola

Member
Apr 27, 2020
16
Denmark
Hi again,
I would say its Dark green in color, or dark gray. I have a pool test kit that measures PH level and chlorine level. I have been told to use chlor - a little bit every day to keep the algae away.

i have one other chemical to use, if PH level becomes too High, and thats it.

another thing - the waterlevel. We have had fairly good weather the past weeks (in DK thats 18-20 celcius and a cloud fred sky) is it normal that the warerlevel drops 4-5 millimeters on such days - or do i have a leak.
 

jetola

Member
Apr 27, 2020
16
Denmark
Just a thought. My pool have a metal Walls, and i discovered the sinking waterlevel after we for several days have had a rise in temperaturer in DK from around 10 celcius to 15 celsius. I know it’s means some more Will vaporise - but could it also be because the pool expands a bit as it g’ets warmer ?