New Member needs needs help with INTEX Krystal Clear Sand Filter...

[BeerEye55]

I am a new member to TFS and originally posted this in the "Introduce Yourself" area of the Forum but felt like I'd get more reaction here: "Hello, TFP!! I am a new member from Queen Creek, AZ (SE Valley, Phoenix suburbs). I recently put up an Intex Ultra-Frame 18' x 9' x 52" pool in our rather smallish backyard, it is near a few Sissou and Queen Palm trees that drop a lot of leaves and debris into the pool, especially during monsoon season. I am getting ready to install an Intex skimmer basket kit (when it finally arrives from Amazon) to take care of that issue. However, I am having issues with the Sand Filter/Pump - it works steady for about 1.5 to 2 hrs (good suction from both ports, high volume of flow thru the return) and then it starts spitting sand back into the pool thru the return. The pool came with the Krystal Clear Sand Filter Pump (Model SF90110T) and I have been using the backwash, rinse method (also trying to bleed air from pump) before each filtering session, but it keeps doing the same - if I put the timer setting on Filter on more than 2 hrs and leave it unattended, when I come back after it shuts off I will have large streaks of collected sand all over the bottom surface of the liner. I have cleaned out the sand tank and replaced the media, checked all connections for leaks (there are none) and I've tried tipping the pump while opening the air bleed valve to remove any possible air cavitation in the upper pump housing. With the amount of sand that has been pumped back out into my pool, I'm concerned that I may have to take everything apart again and add more sand to bring it back up to acceptable levels. Sorry for the length of this post, but any help that can be offered in the Forums would be appreciated. "

 

[zea3]

Hi, welcome to TFP! Are you shutting off the pump before moving the handle on the multiport valve? Did you use #20 silica sand for the filter? A picture of the filter and the sand in the pool may help.

 

[Jake124]

It sounds like it could be a damaged lateral (the little arms at the bottom of the sand filter). There are tiny slits that keep the sand from going into your return and they're quite fragile.
Has it ever worked correctly or did this start just after filling it with sand?

 

[BeerEye55]

I always shut off the pump before moving the multi-port valve handle to a new setting. I am using Quikrete Pool Filter Sand I bought at Home Depot, on the bag it says that it is silica but does not give a grade number.

 

[BeerEye55]

I will take a picture and post the next time I run the pump on Filter setting for more than 2 hrs. Since initial setup and fill of the pool (about 2 months ago) it has always done this - "Filter" mode runs great for about 2 hrs, then it starts spitting sand into the pool from the discharge/return. The sand does not come out in a copious amount, it just makes the water coming out the return a little cloudy, but if I use the recommended 4-hr filtration time frame for my pool and leave some time for it to settle I'll see that a fairly decent amount of sand is ending up on the bottom of the pool, pushed into streaks in the middle and into the corners by the water flow direction of the return.

 

[zea3]

I think the problem is with the Quickcrete sand itself. Quikrete 50 lb. Pool Filter Sand-115350 - The Home Depot

Read the answers under the last question. There is a post from Quickcrete that says their pool filter sand is a mix of #20-40 and that the finer #40 sand is not compatible with all sand filters. I think if you replace the sand with true #20 silica sand that should fix the problem. While the filter is empty inspect the laterals for cracks.

HtH brand filter sand gets pretty good reviews.