Newbie, I think I know the answer but....

[healthservices]

Several problems with the pool and a support items hopefully a couple can get worked out here.

I have a DE filter hayward pro grid (?) couple years old and a Hayward Northstar pump and a anthony pool made in the early 60s with 1.5 inch pipes(?). Not sure the size of the filter but I put about 12 blue cups of de after removing the filter assembly to hose off. Pressure is about 12-15 PSI at the tank.

Now here is the problem, I have kreepy krauly that seems to be working great. Dirty and a bit cloudy pool, with some algae that floats and clumps together, making it look like floating dog poo. The kreepy krauly works great at first and pressure is at 15 psi, but after about 15 minutes the filter pressure jumps to 25 psi and the kreepy krauly stops moving until I back wash it and start over.

[Watermom]

Is it live algae? If so, live algae will clog a DE filter fast. Kill the algae first. Give some more info about your pool (type of pool, volume, size of pump) and give some current water testing results taken with a drops-based kit. Then someone here will try and help.

Welcome to the Pool Forum, by the way!

[healthservices]

Pool is about 18k gallons so it is not a big pool. Gunite and plaster pool. I have to figure out how large of a filter I have. As for the algae I think most is dead now. but what is there is greenish brown and looks kind of like diarrhea, when you try to scim it off with a net it breaks off into pieces and goes right through the net.

As for a test I have yet to do one yet.

[healthservices]

I just went back outside and back washed it again. what comes out is white and not discolored. pressure is back down to 13-15 for the time being. I only put 2 scoops of de this time since I'm running out. Pool looks fairly clean except for the floating algae, and it being cloudy. I'll just use the skimmer to see if I can get the floaties out.

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Could my Grids be plugged up and need a acid wash? If so why would the tank pressure be so low (13-15 psi) when I start off with a fresh charge of DE?

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Or maybe my pump is bad? But why would it go to 25 psi?

[PoolDoc]

As Watermom pointed out, DE filters clog almost instantly when live algae is present; you have to add enough chlorine to kill ALL before you are going to get adequate filter performance. With a gunite pool, there's no problem with high chlorine even if you have no stabilizer.

So do this:

#1 - Add 7 gallons of plain 6% household bleach tomorrow morning, and
#2 - Add 10 gallons of plain 6% household bleach tomorrow EVENING.

Meanwhile, if your filter has a valve with a "Recirculate" setting, use that, till the algae is dead.

[healthservices]

So when do i know if the algae is really dead?

I'll be getting a couple gallons of liquid chlorine this morning.

If the picture will upload this is what it looks like today after about 6-7 back washes
.

Hopefully by months end i will be able to take a dip in the pool.

EDIT by mod: Send your pics to poolforum AT gmail DOT com and reference the URL of this thread and we'll get them added

[healthservices]

Duh, I just noticed you said bleach and I'm used to using the 'bleach' and 'chlorine' as one in the same. Can I go with liquid chlorine and will I use the same amounts?

Thanks

[Watermom]

You can use liquid chlorine. Unless it is also 6% (and I doubt that it is), you'll use different amounts. Tell us the percent sodium hypochlorite and we can calculate a dosage for you. An easy rule of thumb that may help you judge is that in 10K gallons, the percentage of chlorine will add that amount of ppm to your water. Example -- in 10k gallons of water, a gallon of 6% will add 6ppm, 12.5% will add 12.5ppm, etc.