First time pool owner, DE filter question

[gundan]

Hello,

We purchased our home in New Jersey last september with an in-ground 28,000 gallon pool serviced by a Pentax DE 60 sq feet filter. When we closed the pool, we took the DE apart and cleaned everything out and further put it back together when we opened up last week. When I started things up I added about 9 scoops of DE over 2 days(as recommended by pool opener). The pool was initially cloudy but then I ran the pump for about 2 days and it cleared out very nicely.

The pool looks great and the water is clean, yesterday on the recommendation of some friends I took a sample of the water to the local pool store and the pool dude sold me some of this phos free stuff which he told me to dump 1.5 liters of it into my skimmer and let the pump run for 24 hours and then add another 1.5 liters and run for another 24 hours. I dumped the first 1.5 liter and started the pump and I noticed that the DE pressure spiked up within about an hour to the 30 psi level. I did the backwash/rinse cycle and further refilled just 1 scoop of DE and let it run over night. Earlier this morning I saw that pressure was back up to 30 psi.

Late last night I was reading up on the pool chemistry stuff and I read a lot of comments about the pool store chemistry being a bit dodgy and the phosphorous stuff is not that important, but it is more important to get a handle on the overall water chemistry as outlined in the tutorials here. I have now ordered my pool testing kit(Taylor Instruments). Here are my questions.

1. Even before I added this phosphorous reducing agent, I felt that the DE pressure was spiking up quite a bit quite quickly, do I have to do a full clean up of the DE and start afresh?
2. After I backwashed I know I added too little DE, would that cause the issue of the DE pressure spiking high? When I get home later this evening do I just add the recommended 4-5 scoops of DE and start the pump on again?
3. How long should I run the pump everyday? 5 hours?
4. Did this Phosphorous reducing agent cause my filter to start working harder & hence the higher pressure?

Thanks much!

 

[JohnT]

Welcome to TFP!

You don't say which model filter you have, but a 60sf DE filter probably needed all of that 9 scoops or more as soon as you turned the pump on. Running a DE filter without sufficient DE can cause grid clogging.

After backwashing, one scoop isn't enough to recharge the DE. Again, I don't know which filter you have, but you may need to put the full amount of DE into your filter after backwashing.

It's possible you may need to clean your grids to get back to normal operation, as the effects of running with insufficient DE can't be cleared by backwashing.

It's also possible that you are just seeing your filter do a good job of removing stuff from the water which can require frequent backwashing. If your water chemistry isn't right, you could be fighting a slight algae battle which is being mostly filtered out.

 

[steveg_nh]

I've never heard of adding DE over the course of 2 days. If you clean, you immediate recharge. If you just backwashed, you use about 80% of the full amount. If you opened it and cleaned it thoroughly, you use the full amount.

 

[gundan]

Hello JohnT

I have a pentair fns plus de filter sized at 60 sq feet.

Thanks
Gundan


Sent from my iPhone using Tapatalk

 

[gundan]

Hello JohnT & SteveG

I have a Pentair FNS Plus Filter 60 sq feet filter. From the math I have done, I need 8 lbs of DE on a fresh charge and about 5-6 after a back wash?

I am looking forward to my testing kit and further getting my water chemistry right hopefully soon.

Gundan

 

[Richard320]

If you read all the claims about phosfree, it's doing what it should be and reacting with the phosphates and loading up the filter.

I'd suggest opening up the filter again and having a look-see. Since it was thoroughly cleaned not long ago, a total teardown may not be necessary. I leave my grids in with the backwash valve open and attack them with the jet stream spray nozzle on the hose , then close it up, give it one last brief backwash to flush it all out of the hose, and load it up with the full amount.

 

[gundan]

Thanks for all your feedback, it has been very useful. I will be getting my testing kit tomorrow and am looking forward to it.

Btw, where do I store the liquid chlorine that I am planning to buy? It is being sold locally for $3.85/gallon and I have a 5 gallon container. Can I store this in my basement? or garage?

 

[JohnT]

Thanks for all your feedback, it has been very useful. I will be getting my testing kit tomorrow and am looking forward to it.

Btw, where do I store the liquid chlorine that I am planning to buy? It is being sold locally for $3.85/gallon and I have a 5 gallon container. Can I store this in my basement? or garage?

I keep mine in the basement. Cooler and darker is best.