DE Filter Flow Issues

[dogtag13]

Hello, I've been fighting a filter issue since May on my 35 year old pool. So far I've replaced the back flush valve, filter grids and the filter manifold all of which were faulty. My issue now is that I clean the filter and I get great flow for 20 minutes with the water cascading over my hot tub into the pool. Then after 20 minutes the it stops to a trickle of even completely with my pressure gauge pegging at close to 40 PSI. I can backflush and it will be good for maybe 5 minutes. With all of these issues my pool is a dirty mess but when I remove the the grid it isn't too terrible. I'm thinking the problem may be with the aftermarket manifold which has a few vent holes where my original manifold had a removable stainless steel hemispherical screen. The filter grids were aftermarket also but i can't image that is my problem. I really need to get this sorted before the temps drop below freezing. Any ideas as to what is causing my flow issues would be greatly appreciated?

 

[ajw22]

What model filter are we discussing?

Do a Overnight Chlorine Loss Test . Usually that clogging behavior is caused by algae clogging the filter.

 

[Jimrahbe]

13,

You have a chemical issue not a mechanical issue.. Your filter is doing what it is supposed to be doing..

You have algae, even if you can't see it yet.

If you water is green, then SLAM or replace the water... I suspect that water is cheaper than Liquid Chlorine right now.

If your water is not green or cloudy, then do the Overnight Chlorine Loss Test.. OCLT

Thanks,

Jim R.

 

[dogtag13]

Thank you both. Water is definitely green but the filter didn't seem clogged to the point it would restrict flow. However, I think a drain and refill is in order.

 

[Texas Splash]

However, I think a drain and refill is in order.

We would hate to see you waste money and water draining if not needed. Since your description sounds like algae, you could start the SLAM Process now. That is if your have a TF Series test kit or Taylor K-2006. Even if you exchanged your water, I suspect there would be residual algae and you would still need to perform the SLAM Process. At the very least do an Overnight Chlorine Loss Test. Now is the time with the cooler weather dropping in on us.

 

[proavia]

How are you testing your water? Test Kits Compared

How are you chlorinating your water?

If you have green water, you need to SLAM Process

 

[Jimrahbe]

We would hate to see you waste money and water draining if not needed.

Pat,

I can completely drain and refill a 15K pools for about $75 bucks..

What much do you think a SLAM is going to cost if the water is green???

The more Liquid Chlorine costs, the less and less it makes sense to SLAM..

Thanks,

Jim R.

 

[Getitrite]

So far I've replaced the back flush valve, filter grids and the filter manifold all of which were faulty.

Your grids appear to me to support the algae diagnosis. I would expect them to be almost as "White" as the new manifold. (I see more of a "Green" tint.)

This is from my Hayward at the end of last season after Backwash, removing, and then rinsing with the water hose. For many years (before TFP) mine would look like yours - and worse - several times a season.

 

[Texas Splash]

What much do you think a SLAM is going to cost if the water is green???

Jim, I certainly support drain if warranted and have recommended such in the past to others. To each his own. Each scenario is different. If it's cheaper between water and chemicals, plus safe for that pool, no worries. Owner's choice.