My normal source of chlorine for the season wasn't available this year so I've been trying to find something else. I found 90# of 48% cal hypo on sale for $1/lb. Doing the math revealed that at $1/lb it was much cheaper than I've been able to find for any liquid chlorine around the Seattle area. I have to add CH each year due to the amount of rain (and snow this year!) that we get so the added CH from the cal hypo would work well.
After getting it home and opened up I think I know why it was on sale. It isn't hard as a rock but pretty close. The whole bucket is like this. Given the moisture in the air here sitting around for a year or so could have an impact. At any rate I figured I would pre-dissolve some in water and added to the pool as the start up dose for opening to see if it worked. I added 3 pounds which should have given me 7.8 FC. I tested about 30 minutes later and yielded only 0.5 FC and 0.5 CC. Given that it was the start most of the chlorine could have been consume quickly. I pre-dissolved another pound and added it. This time I tested within 15 minutes and took the water sample where FC concentrations are usually higher just after being added. Again, only 0.5 FC and 0 CC. I thought it could have been my kit so I got out reagents that I purchased last year. Same result. Some of the DPD powder is older but it has always been spot on. In the past openings I've added 2 gallons of 10% bleach and FC went to 9 and drifted down slowly. The pool this year doesn't look all that different in the past years so I would expect the addition of 10 FC to yield higher than 0.5 FC when testing.
This got me thinking about the cal hypo being solid. Is there any merit to the thought that if the cal hypo has gotten moisture in it the amount of available chlorine would be reduced? It wasn't dissolving to well and there were a lot of white particles floating on the water. I'll sort that out later but I need to figure out if I have to track down another source of chlorine or if something else is at play. I plan on doing a concentration test tomorrow night so I'll have more data then.
This is my first time using a non-liquid chlorine so I'm a little unsure of what to expect. If anyone knows a good source of liquid chlorine in the Seattle area that would be great too! I refuse to pay $5/gal for 10% bleach at Ace.
Any help is appreciated.
Matt
After getting it home and opened up I think I know why it was on sale. It isn't hard as a rock but pretty close. The whole bucket is like this. Given the moisture in the air here sitting around for a year or so could have an impact. At any rate I figured I would pre-dissolve some in water and added to the pool as the start up dose for opening to see if it worked. I added 3 pounds which should have given me 7.8 FC. I tested about 30 minutes later and yielded only 0.5 FC and 0.5 CC. Given that it was the start most of the chlorine could have been consume quickly. I pre-dissolved another pound and added it. This time I tested within 15 minutes and took the water sample where FC concentrations are usually higher just after being added. Again, only 0.5 FC and 0 CC. I thought it could have been my kit so I got out reagents that I purchased last year. Same result. Some of the DPD powder is older but it has always been spot on. In the past openings I've added 2 gallons of 10% bleach and FC went to 9 and drifted down slowly. The pool this year doesn't look all that different in the past years so I would expect the addition of 10 FC to yield higher than 0.5 FC when testing.
This got me thinking about the cal hypo being solid. Is there any merit to the thought that if the cal hypo has gotten moisture in it the amount of available chlorine would be reduced? It wasn't dissolving to well and there were a lot of white particles floating on the water. I'll sort that out later but I need to figure out if I have to track down another source of chlorine or if something else is at play. I plan on doing a concentration test tomorrow night so I'll have more data then.
This is my first time using a non-liquid chlorine so I'm a little unsure of what to expect. If anyone knows a good source of liquid chlorine in the Seattle area that would be great too! I refuse to pay $5/gal for 10% bleach at Ace.
Any help is appreciated.
Matt
