back-wash gone bad

[senor.hugo.maria]

dear gents.

i am happy to have found this forum.

today i did a back-wash on my sand-filter. to give a rinse so to speak.
then my wife comes running in a state of panic; yelling: There is brown stuff being injected into the pool.

now, I am convinced i did it correct. setting all the valves as they should be.

in any case, my whole pool (15 x 5 mtr) is now filled with cloudy water from all the sand being pumped into it.

damn damn, double damn.

I am trying to to fix this by:

1) no more swimming
2) running the pump at full power
3) waiting for tomorrow and see if it has cleared up a bit
4) doing a manual suction clean of the floor and walls.

if this all fails, I will have to drain the pool and refill it

anybody any other suggestions ?

thanks
hugo

[Denniswiseman]

Had you previously done a backwash with no problems? If so then it could be a problem with your MPV. Replace your spider gasket
To Backwsh you just alter your MPV to the backwash setting
You shouldn't need to drain and refill without sorting the problem because it will only happen again

[senor.hugo.maria]

Unfortunately i am not that lucky to have an MPV. It is an older system.
[img]https://uploads.tapatalk-cdn.com/20170821/d031ef8556e34c2e45dad950d11c59a9.jpg[/img]

Guess i am gonna have to inspect all the valves for defects so it wont happen again.

The good news is that the pool has cleared up significantly with most of the sand laying on the floor. I have got some work ahead of me, but no need to drain and refill.

[Denniswiseman]

Right having a look at that image explains everything. It seems that you had one of those valves in the wrong position
Check you have them in the right position when backwashing.
The pump flow should be going into the bottom of the filter and coming out of the top to the drain
I can't see where the pump is
Those valves look ok but it may be worth taking the handles off to check that they are turning 90 degrees

[senor.hugo.maria]

Yeah.
As soon as i have done my daily duties (we are operating a BnB on Mallorca) i am gonna take all the valves apart and give them a little service

I do remember that when i did the backwash, i indeed routed the pump exit to the bottom entry of the filter. And routed the top entry of the filter to the exit-to-drain pipe.

I still have no idea what went wrong.

If i find something wrong with the valves, i post it here.

Thx anyway for your input

[Denniswiseman]

You may have left one of the other valves open allowing dirty water to return to the pool
I good idea is to take photographic evidence of where the valves should be future reference

[senor.hugo.maria]

All the valves are A-1-ok.
I must have messed up; opening the valve between the intake and exit tubes.

[senor.hugo.maria]

Question:

With a sandfilter.
When having done a backwash
Does one need to wait a certain time before returning the valves back to normal operation??
To let the sand settle so to speak.

[Denniswiseman]

I never wait
I backwash until the water runs clear
Stop the flow
Rinse for about 10 seconds to waste
Stop the flow
Then turn back to filtering
I know you don't have MPV and you may not be able to rinse

[senor.hugo.maria]

Yeah. I guess it is an old-school installation

[Denniswiseman]

It still works though and you don't have to worry about spider gaskets
Just take some images of the correct positions of the valves for filtering and backwashing for future reference