Green DE

[barneye]

I have a Hayward DE 4800 and have ordered new filters because there is DE all over my pool. It appears the previous owner stopped adding DE after backwashing for this reason and failed to disclose to me. I added two one pound coffee cans of DE before noticing the DE coming out the returns. What a mess! It may be coinsidental but it looks like the DE turned green and now the whole pool is green. I have checked all the chemicals and everything is right on.
I am planning to install the new filters in the next few days (when they arrive) my questions:

1. should I install the filters and add DE before vaccing the pool? Or should I vac first then backwash and then add DE? I do not want to add too much DE.

2. How much DE do I add after changing the filters and how much at each backwash?

3. Does DE turn green when in chlorinated water? I have balanced, shocked and added the reccomended amount of algecide and it has not helped much. (Been about 15 hrs since treatment)

[superdoopie]

1. should I install the filters and add DE before vaccing the pool? Or should I vac first then backwash and then add DE? I do not want to add too much DE.

If you have a multiport valve on the filter you can vacuum to "waste." If not then add half the ammount of DE required, then vac out the DE and immediately backwash or take the filter apart and manually clean the grids.

2. How much DE do I add after changing the filters and how much at each backwash?

This depends on what the filter area is. It's measured in square footage and should be 48sqft since you have a Hayward 4800. Since you just bought grids you should know this number. Then refer to the de you buy. There should be a chart on the bag.

3. Does DE turn green when in chlorinated water? I have balanced, shocked and added the reccomended amount of algecide and it has not helped much. (Been about 15 hrs since treatment)

DE shouldn't change color. It sounds like you have algae and it's most likely because the filter grids are torn and not filtering properly. You'll need to brush the walls and floor of the pool to get it into the water then superchlorinate and filter continuously. Also backwash frequently or manually clean grids until it's gone.

[czechmate]

Algae will coat DE green.
You have either loose manifold /element connection, or grid damaged by chlorine.

[Guest]

Turned out to be a cracked manifold that the previous owner jerry rigged with epoxy or plastic cement, hard to tell. Took the new grids to the pool supply and bought the manifold, the tech/owner put it all together for me while I waited, took three guys 30 minutes to get it together, glad I didn't try it at home!
Anyway, less than 12 hours later the dark green swamp is crystal clear blue again. I tried to vacuum to waste before the green was gone but gave up after a few minutes of not being able to see what I was doing. Put it on filter and went to bed and woke up surprized. Thanks for your help!