The more dilution on the CYA test the less accurate it becomes. I would be more suspect of the 4 to 1 CYA test accuracy than the CH test. Still gets to the same answer though, drain more. 
AA Treatment then Partial Water Drain
- Thread starter aeh0603
- Start date
I did the second water drain this morning and removed a few more inches than yesterday. Pool is once again refilling slowly while I'm at work, and I'll post the numbers again tonight once all the water is mixed up. I did add about a quart of 10% bleach this morning which with my reduced water volume should raise FC to the 3-4 range. There is visible algae in a few places so I'm mostly just trying to keep it from getting worse at this point. Once the pool is full, between the dilution, residual AA, and the algae I don't expect to see much, if any, of that in my measurement tonight.
Here are the new measurements:
FC: 0
CC: 0.5
pH: 7.6
TA: 120
CH: 500
CYA: 80
I need to drain again don't I :/ What CYA level should I be targeting?
FC: 0
CC: 0.5
pH: 7.6
TA: 120
CH: 500
CYA: 80
I need to drain again don't I :/ What CYA level should I be targeting?
No, I wouldn't, CYA at 80 is manageable, especially in your sunny climate, it will reduce your daily chlorine loss. You probably want it at 60 anyway, what's another 20? Nice work! Put some chlorine in there. Keep FC at target and don't let it drop below minimum, ever, to keep your pool sanitary and algae free. Chlorine CYA Chart
With CH high-ish, and likely to climb, keep an eye on your CSI score in Poolmath. Keep it between 0 and -0.3 to avoid scaling.
More here, Pool School - Calcium Scaling
And here, Langelier and Calcite Saturation Indices (LSI and CSI)
With CH high-ish, and likely to climb, keep an eye on your CSI score in Poolmath. Keep it between 0 and -0.3 to avoid scaling.
More here, Pool School - Calcium Scaling
And here, Langelier and Calcite Saturation Indices (LSI and CSI)
Oh, oops... well I already finished draining again and its refilling right now. I do have a big bucket of dichlor (purchased before finding this site) if I need to raise CYA later.
I finished filling the pool before I went to sleep last night. I added about 3/4 of a gallon of 10% bleach (to add about 6 or 7 FC) and let the pump run overnight. I brushed the pool this morning before testing (there was a little bit of algae on the walls).
Here are the numbers:
FC: 8
CC: 0.5
pH: 8.0
TA: 130
CH: 450
CYA: 40
Here are the numbers:
FC: 8
CC: 0.5
pH: 8.0
TA: 130
CH: 450
CYA: 40
So what is next? Do I need to wait to SLAM my pool since I just did the AA or is it safe to SLAM since I drained the water? I'm also thinking I should wait to add the metal magic until after the SLAM so it doesn't get consumed by high FC. Does that sound right?
Oh, I forgot to say that I added acid after the original test this morning and lowered my pH to 7.6
Oh, I forgot to say that I added acid after the original test this morning and lowered my pH to 7.6
I'm keeping my fingers crossed that when you SLaM you will find no stains!! With all the water change I would hope you are below the staining threshold
I hope so too! I didn't actually use enough AA to get rid of all the stains. You can still see some in the pictures with the water drained, and there is still a bit on the bottom of the pool. That said, the pool looks SO much better, especially the steps. I will probably treat again with AA the next time I need to drain large amounts of water (presumably I will have to do that periodically to lower CH).
As for right now, I'm happy with how much improvement there is. I guess I will cross my fingers and start the SLAM when I get home from work. I will wait to add the Metal Magic I bought until after I pass the SLAM and FC returns to normal. The MM may reduce the remaining stains, if not I won't bother with it again. I'm hoping to avoid the need for a maintenance dose but I guess I'll cross that bridge if it comes.
As for right now, I'm happy with how much improvement there is. I guess I will cross my fingers and start the SLAM when I get home from work. I will wait to add the Metal Magic I bought until after I pass the SLAM and FC returns to normal. The MM may reduce the remaining stains, if not I won't bother with it again. I'm hoping to avoid the need for a maintenance dose but I guess I'll cross that bridge if it comes.
I started the SLAM and so far so good. I lowered the pH to 7.4 using MA per pool math and it did exactly what I expected. After letting the pump mix everything for a while I then added bleach per pool math to get me from FC 4 to FC 16. I tested after a while and FC is now 20... playing with pool math it looks like my 10% bleach from Wal-Mart may actually be closer to 12.5%.
Well that was a quick SLAM, I passed OCLT last night with a loss of 0.5FC, CC is 0 and I didn't see any algae when I brushed the pool this morning! I'm calling it a win! I also didn't notice any new staining (from metals).