Sand filter problems, maybe not working?

[chimerahitman]

Hello TFP,

I have been noticing particles coming out the jets when cleaning the floor of the pool with the suction hose doodad. More specifically whenever I run into a dirty patch. I see bits of leaves I pick up.

The strange thing is that when I run the pump for daily maintenance, 3 1/2 hours a day, it comes out clear. Both times are run in filter mode.

The filter was cleaned when I moved in the house about a month ago. The sand was taken out and moved about because it was sorta caked up, also the finger bits at the bottom of the filter were cleaned. Then put back together, some sand was lost because it was not possible to recover. Then it was backwashed, rinsed and finally set to filter where it has stayed until today. The starting pressure was noted of 9 psi. Coincidentally I have noticed that when I start the pump it stays at 8 psi which not much higher than off and if while the pump is on I switch from filter to something else and then back it comes up to 9 psi.

EDIT: My dad has a similar filter and keeps recommending me a "Pool-Floc" chemical and I have been against it for the most part. Only recently I have been considering it because when I vacuum the bottom it goes from clear to some what cloudy appearance.

Data: Swim Pro by Hayward Model VL240T, and a Sta-Rite 3/4 HP pump.

Thank you,

 

[mknauss]

Floc is not a good solution to your issue.

Does your pressure gauge go to zero with the pump off?

You said the sand was clumped up (probably from past use of floc or clarifier). It would have been best to dispose of that and use new. I would check your filter for channeling.

 

[chimerahitman]

Does your pressure gauge go to zero with the pump off?

No it does not. With the pump off, it sits at about 7 psi.

You said the sand was clumped up (probably from past use of floc or clarifier). It would have been best to dispose of that and use new. I would check your filter for channeling.

Only the top layer. All of the sand was taken out and then put back in. (EDIT: Well technically some sand was left on the floor, because it was a waste of time to get it all.) It did not look bad, it did have a very strong chlorine smell to it. How would I know if it has channels? Is it obvious holes in the sand?

 

[mknauss]

You need a new pressure gauge.

If the sand refilled OK then channeling should not be an issue. Smelling of chlorine means it was contaminated with something.

 

[chimerahitman]

You need a new pressure gauge.

If the sand refilled OK then channeling should not be an issue. Smelling of chlorine means it was contaminated with something.

I will look into it tomorrow. It is 9:37 pm now. The pool is in ground, but the pump and filter below the water level by about 2 meters.

To test out the gauge I will close all inlets and outlets to the pump and out of the filter and put it in waste position. That should relieve any water pressure in the lines and then the gauge should read 0 psi.

If it is not the gauge what else could it be? So far I vacuum every 3rd day. On that day the water is crystal clear, but after vacuuming it becomes hazy. Over time it feels like the stuff I pick up just gets put back in because it is the same yellowy looking dirt.

 

[mknauss]

A sand filter should not allow debris through it. You mentioned not putting as much sand in as you took out. You may need to add sand to the filter.

2 meters should equate to about 3psi.

 

[chimerahitman]

The doubt is killing me. I will go check with the flashlight and sure the gauge is working or determine it is not.

Does the sand filter have an internal fill level or is there a rule of thumb of how much it should have?

 

[mknauss]

I just searched your filter -- appears it should take 90 kilo of sand.

 

[chimerahitman]

I just searched your filter -- appears it should take 90 kilo of sand.

So short of weighing the whole filtering device I am out of luck in know how much it should have?

I just went to check the pressure gauge and I realized a mistake I made. I made all my measurements counting 5 ticks to 10 psi, but it is actually 4 ticks. Every tick is 2.5 psi. So the measurements I will give from now on are corrected.

I checked closing the valves and it almost drops to 0 psi, it is just above it, maybe 1.25 psi (sits between 0 and 2.5 psi indicators). With the pump off, it has 5 psi. With the pump on, it is reading 7.5 psi and by playing around with the filter positions I can get it to slightly higher than 7.5 psi.

What could happen if I over fill the filter?

 

[mknauss]

If overfilled backpressure can be higher and you may backwash out some sand. I imagine a manual will tell you how high in the vessel to raise the sand. I did not read it that closely.