Adding DE to sand filter

[nanhsot]

We're just coming off a horrible pool week and I've spent an inordinate amount of time in these forums, solving problems, so first of all THANK YOU for the invaluable advice I've received here and in Pool School.

Water is finally clearing and things are mostly under control, so now I'm just reading up on things to further educate myself in hopes of avoiding future problems (ha!). I came across the "adding DE to sand filter" and understand the process, my question is if there are any drawbacks to doing this. We had to replace all the sand in the filter this week and I don't want to do anything to inhibit the regular workings, if adding DE will enhance and add to the longevity of my sand filter I'll do it, just curious if the benefits are worth any known drawbacks.

Any other advice on sand filters? For some reason ours quit working after only 4 years, the sand was packed and gross, seemed too early for that to happen but it's working and clearing our (previously dirty green now just cloudy) water well.

 

[JohnT]

Adding the DE is essentially making your filter a little dirty, which makes a sand filter work better. The DE clears when you backwash.

Sand problems might indicate chemistry problems or overuse of clarifiers or other chemicals that can cause sand to become sticky.

 

[PaulR]

I would think that fresh sand would have sharper edges and work pretty well even without DE. I remember reading recently how somebody had just changed their sand and the water was perceptibly clearer even without a little DE. But basically you see how you water looks once you clear out the mess, and decide then.
--paulr

 

[notvaporlocked]

I just changed my sand after 7 years and within 4 hours could start to see a difference. I am convinced the fresh sharper sand is the ticket.

After about 3 days my pool sparkles. I was tempted to try the DE powder thing but finally decided to just change the sand. In my case it cost me around $120. In the future when the performance starts to drop I may experiment with the DE but for now I don't see any need.

Terry

 

[pool4me]

I agree,

It's very hard to see any difference adding DE to brand new sand. After the sand begins to "dull", you can notice a difference with DE. I too changed my sand this year so I won't go back to a little DE inthe filter until the end of next season or possibly the season after that.

 

[haybird]

My pool was always sparkling. After a screw up replacing an O-ring we had to have our sand replaced. The pool then always started to look a little dull. Not cloudy

Did an overnight test and the FC held to the drop. Started reading about sand being to clean, so I added a little DE. Within 1.5 hrs my pressure was up 10psi from 15 to 25. I have repeated this a couple times and my pool is starting to sparkle again.

So in my case it seems my sand was to clean and adding a little DE helped. Unless somebody has some other theory?

 

[mickey4paws]

I just got a new sand filter. I have been using a skimmer sock, but now I wonder if I should remove the sock for a while so the sand can get a little dirty (?)

 

[NWMNMom]

We added a bit of fresh sand this spring - after several years with the same sand, we found that we were essentially backwashing away sand each time we did that and got very low. The additional fresh sand helped but we did top off with a bit of DE - and I do that after each backwash, which I do sparingly - only if we have an algae bloom. Proper water chemistry will reduce the amount of backwashing required but vacations and poor upkeep by the teenagers while gone often leads to inevitable mini-blooms. DE polishes up the water. I keep a box on hand all the time and add 1-3cups as needed.