New Home/Pool Owner Baffled

[Utlmnop]

I'm really sorry this is so long – but I’m desperately seeking direction.
A week ago, my husband and I bought a house with a pool (pool stats below in signature). The previous owners opened the pool when they listed the house in December, and it appears that they were just chunking a bag of Walmart powdered shock in the pool every few days, but no other maintenance was done.

I bought a K-2006 test kit and began tackling the pool immediately. The pool is unbelievably clear considering I can’t keep FC in the thing to save my life. I know (NOW) that I should have been dumping bleach in the pool more frequently – and plan to remedy that beginning tonight.

The Issue

The pool gets direct (and I mean FULL ON DIRECT) sunlight from about 9:30 am until about 7:30 pm. I’m concerned that because of the sun, I'm not getting the shock level high enough, and that the other chemical levels are causing the system to be out of balance. Again – the pool appears clean – so much in fact that we’ve taken a dip a couple of times with no ill consequences (to us at least). The CYA mix bottle was missing from my K-2006 kit (a replacement is on the way). The last time I took a water sample to the pool store – the CYA was 75. The filter has been running 24/7 and the PSI is between 8 and 10. We had rain every day last week, so I ended up backwashing about 4 inches of water out of the pool last Friday. I haven’t backwashed this week. Prior to last night, I was adding roughly 2-4 bottles of 6% bleach to the pool daily.

Last night at dusk, I added 6 gallons of 12.5% LC to the pool (the recommended shock value to get the pool to a FC=31 with a CYA of 75) – I tested about an hour later and got the following results:

FC: 1.8
CC: 1.0
pH: 7.2
TA: 120
CH: 290
CYA: ??

According to the pool calculator, I needed to add another 4.8 gallons of bleach and some borax to bring up the pH. I added 5 gallons of bleach and a box (77 oz) of borax (this was about 10 oz short of the recommendation).
After 45 minutes, I tested again.

FC: 28
CC: 0.5
pH: 7.4

This morning (before dawn)– I had 0 FC, 1 CC – and a pH of around 7.3

So again – my question is – with a past CYA of 75 – should I be adding bleach to get to a FC level of 30-31 every hour until the FC stops decreasing? Or because of all the direct sunlight, should I be trying to push it to a FC=40-44 number? Are the other chemicals playing a factor? With a CYA of 75+ -- is this a hopeless cause without draining (I really really REALLY don’t want to drain – the cost of H2O is outrageous right now)?

Finally: We inherited a Polaris 180 – should we be running him during the process or should he stay out of the pool until we’re done shocking?

 

[csigirl]

You are not done shocking until you have a free chlorine loss of less than 1ppm overnight.
See Shocking your pool section.
and I wouldn't use your Polaris until you can maintain lower FC levels.
I had the same problems you are currently having and it took me a week of maintaining constant shock levels and scrubbing the pool EACH day until my FC stayed relatively level.
Remember with a higher CYA you will have to add more chlorine, more often regardless. If you can afford to do it, trying draining half your pool to at least reduce the CYA levels...it will help you use less chlorine and save you money in the long run!

 

[Utlmnop]

Looks like I'll be living with the pool calculator for the next few days or so. My husband's family is planning to stop by the new house on Saturday for a BBQ/Birthday shindig. Is it a horrible idea to let people swim? (keeping in mind, I've learned my lesson and will begin shocking hourly/every other hour beginning tonight thru tomorrow evening).

Also -- If I can't get the FC up and somewhat stable in the next 24 hours -- how bad is it to dump a bunch of Bleach into the pool, then go to work and start again when I get home? Is it all for nothing at that point? I'm assuming the with the direct sunlight, there won't be much, if any FC in the pool when I get home.

 

[Bama Rambler]

You need to know your CYA level to properly shock your pool. If you're pretty sure it's 75 then use that as the level.

We all understand the need to make a living so you have to do what you have to do. I wouldn't raise it way above shock level but some won't hurt anything. Just get back after it as soon as you get back home.

 

[Utlmnop]

I'm working from home tomorrow (other house issue requiring me to be home to let contractor in -- yippie for "new" old houses) -- which is how I plan to shock the bejesus out of the pool. I figure I'm safe to assume that I need to only worry about LC right now. Once I can get my FC stabilized, I can focus on anything else out of balance?
Oh -- I forgot to mention I have these four legged bugs that seem to fall into my pool at night. I have no idea what they are (they aren't water bugs), but the skimmer baskets are usually full of these bugs in the morning (20+ bugs in each basket). Could this be another cause of the low FC?

 

[Bama Rambler]

The bugs probably don't use up much FC. It's easy to account for them with the normal levels.

 

[Poolschoolgrad]

Here is a way to test your CYA without the special mixing bottle.
You can use a clean disposable water bottle which has a sport top. The sport top makes it easy to drip the test mixture into the cya tube.

The CYA test is 7 ml of pool water sample combined with 7 ml of R0013.
1/2 TABLEspoon is approximately 7 ml.
Carefully measure 1/2 TABLEspoon of water sample and add to 1/2 Tablespoon of R0013 regent.
Mix thoroughly for 30 seconds. Slowly add mixture to the small cya tube until the black dot at the bottom of the tube disappears.
Read the CYA concentration on the back of the tube.



PSG

 

[Utlmnop]

Thanks PSG -- I'll plan on doing that tonight!

 

[Utlmnop]

**Update**

Taking PSG's suggestion, I calculated my CYA last night -- it was at least 100 (it looked like it barely made the 100 bar). I started the evening by backwashing the filter and was apparently so good at it that I ended up draining a bit too much water out of the pool. Keep in mind that we JUST moved in -- so I ended up digging in the garage for about an hour to find a hose so I could refill the pool (why can't anything be easy??)

It's been a about 12 hours and I've had my pool up at shock levels (FC=35-40) for at least the last 11. The last test I performed last night had my FC=35, and since the pool has been notorious for eating chlorine during the night, I dumped 4 182 oz bottles of 6% in and prayed that would hold out until this morning. This mornings test showed a FC level of 35 -- so I'm still losing chlorine, but I'm still at my "shock" levels.

My CYA test today showed a CYA of 75 ?? I know I didn't dump out that much water -- so I'm not sure if my first test was wrong or not. With a CYA of 75 -- I'm well above my shock levels.

Oh - and my CC = .5 (it was barely pink this morning but did take a drop to clear up)

I know the three rules about when you're done shocking -- I plan to perform the overnight FC loss test tonight --my best guess is that I'm still going to be losing chlorine, just not as rapidly. So I guess my question is -- when I pass all three points -- do I just let the FC levels decrease until they're at the recommended daily levels for my CYA?

 

[twoolley]

CYA levels above 100 usually read incorrectly and are actually higher than that. I just did this last week with a water replacement becuase we bought a house that had 100+ CYA and it took 3 partial drains to bring it to 65...

Have you gotten your mixing bottle yet? If you don't want to use teaspoons I have also found the medicine droppers for infants to be helpful for this and the pH tests.

Remember to add drops until the circle is completely gone, no shadow at all.

 

[BadOleRoss]

Yes, once you pass the overnight test you can let your FC levels fall to the level that is inline with your current CYA, but you really need to get an accurate CYA number. You mentioned your CYA dropping from 100+ to 75, that would require you to replace 25% of the pools water. Once you get the pool right BBB is very easy. Have you ordered a Speed-Stir yet? Once you Speed-Stir, you'll never go back.

 

[Utlmnop]

I'm hoping once the rest of my CYA testing parts arrive from Taylor, I'll be able to replicate my CYA results. I did put fresh water into the pool yesterday, but only about 2-3 inches -- not 25% of my pool, so I'm going to call user error on one of the two CYA tests performed.

I remember using something similar to the Speed-Stir during my Organic Chemistry days - I'm going to have to order one of those -- for the pool of course.

 

[Utlmnop]

Hey all -- quick update. Last night before bed my FC was 30 ppm. When I got up this morning (slightly after dawn -- it wasn't dark but the sun wasn't "up"), the FC came in at 29.5 ppm!!!! Woohoo!!! The pool was clear but my CC was .5 (again - barely pink but not completely clear when testing).

I didn't add any chlorine today -- since the totals were so high and it appears that I've 'passed' the three shock tests. However, after a day -- the chlorine was down to around 22 today -- which has me wondering if I'll lose 8 ppm every day due to the sun and if that's normal or if I'm truly not out of the shock phase ??

My husband has family in town tomorrow - We were planning on swimming -- as long as the chlorine levels aren't too high and the pH is reasonable. I did add about 1.5 of water after my last test today and will likely need to add a bit more tomorrow to get the levels back up to where they should be -- which will dilute the chlorine -- I'm just concerned about it getting too low tomorrow.

Anyone strongly discourage a day of swimming? Can I (or should I) add some 6% tonight before bed or first thing in the morning tomorrow??

 

[BadOleRoss]

As long at your FC levels are below the recommended shock level for your CYA swim away. In my experience, the FC that is above your recommended levels will drop faster than normal. I believe this is because the CYA is not stabilizing the chlorine. When I have a heavy swim load in my pool I will raise the FC level up slightly (1-2ppm) so I dont get any surprises.

 

[mynewpool]

From what I have read, FC loss is a percentage. So the higher the FC level the more of a drop.

Example

10% of 20=2 is a higher number than 10% of 10=1. So once it comes back down, your loss will be a normal loss.

 

[anonapersona]

You might keep in mind that 25% loss number (drop from 29.5 to 22 in a day). That reflects your CYA number, whatever it is. Keep track of future FC declines, you can begin by expecting FC to drop by at least 25%, then some more for the swimmers in the pool. Not an absolute, but something to begin with, your mileage may vary.

 

[Utlmnop]

Thanks all. Everyone had a wonderful time and the pool was sparkling clean! However, it now appears that I have a leak somewhere in my liner.