FC dropped drastically over night

[mattwm]

Hello-

Trying to get my pool balanced and having a little trouble keeping my FC up. 12,000 gal AG pool.

Using Taylor 2006 kit (bold represents values measured this morning):

PH = 7.8-8.0 (just added some MA to reduce this; was 7.2 Thursday night but apparently added too much ph+ last night)
FC = 12 ppm Thursday night, 6 ppm last night, and 3.4 ppm this morning
CC = 0.5-0.6 ppm (tested water was almost clear after 2 drops); this was lower a couple nights ago
TA = 60 ppm (last night)
CYA = 50

I understand TA is low so I will adjust for that.

I've had to clean my DE filter twice over the past week and both times the grids were completely green, however a lighter shade the second time. Should I assume that because of this and a high CC I have a bad algae problem? Water is clear. Hoping I don't have to SLAM.

 

[woodyp]

6 ppm last night, and 3.4 ppm this morning

There's your own answer in needing to perform a SLAM.

 

[Richard320]

^^^ what he said.

And the sooner you start the less algae you'll have to kill so it will go faster.

 

[mattwm]

Thanks guys. Should I use straight household bleach? I have a gallon of shock treatment, 12.5% sodium hypochlorite. Looking in the Taylor manual I believe i'll need two gallons of this to get FC up to 20ppm.

 

[Richard320]

Thanks guys. Should I use straight household bleach? I have a gallon of shock treatment, 12.5% sodium hypochlorite. Looking in the Taylor manual I believe i'll need two gallons of this to get FC up to 20ppm.

Poolmath says 209 ounces of 12.5% to go from 3>20 FC. 1.6 jugs. Remember that's just to get it there. Keeping it there will take more.

 

[mattwm]

Making progress. 2 ppm loss over night and almost no CC.

I had an issue yesterday when cleaning the filter. I hosed off the grids and buttoned everything back together. After adding the DE I discovered a leak at the filter o-ring. After draining and resitting the filter, do I need to add back the DE? Or can I assume the grids are sufficiently covered still?

 

[Richard320]

Making progress. 2 ppm loss over night and almost no CC.

I had an issue yesterday when cleaning the filter. I hosed off the grids and buttoned everything back together. After adding the DE I discovered a leak at the filter o-ring. After draining and resealing the filter, do I need to add back the DE? Or can I assume the grids are sufficiently covered still?

Vacuum it up and it will end up in the filter again.

 

[mattwm]

Vacuum it up and it will end up in the filter again.

Sorry Richard320, not sure I understand. The leaked occurred outside the pool so all the water entered the ground. I just don't know if draining the filter via gravity will result in poorly coated grids. I only had the pump running long enough to add DE before I discovered the leak and shut everything down. I can redo everything just didn't know if it should be a concern.

 

[Richard320]

Then you should recoat the grids. If you're uncertain about how much, backwash to remove any left in the filter and then recharge.

 

[mattwm]

Then you should recoat the grids. If you're uncertain about how much, backwash to remove any left in the filter and then recharge.

Roger that. Thanks.