Joe L Posted May 4, 2009 Report Share Posted May 4, 2009 Sorry in advance if this has been covered, I'm new here. I've got an inground vinyl 32' x 16' pool and replaced the solar blanket late in last years season with a slightly heavier clear one. I've been using standard blue solar blankets for years and was told (by a sales dept) that I shouldn't see a dramatic change in chemical usage. That wasn't the effect however that I observed. I seemed to have a much harder time keeping stabilized chlorine levels up without using a lot more pucks and needed to babysit it much more frequently. So, was I mislead on the clear solar blanket, or could my chemicals be suspect? As the season is upcoming, do I need to consider going back to the blue blanket, trying fresh pucks, both, or even something else. I did get more free heat via the clear cover, but kept the water temperature in the same range as I normally do, around 80 -84F. I'm located in Edmonton Alberta, if that makes any difference. TIA Quote Link to comment Share on other sites More sharing options...
chem geek Posted May 4, 2009 Report Share Posted May 4, 2009 I suggest you check your Cyanuric Acid (CYA) level. If you are only using Trichlor pucks and not diluting the water significantly, then the CYA level will keep climbing and the chlorine will be less effective as a result (unless you proportionately raise the Free Chlorine level). For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases CYA by 6 ppm. You can read more about the chlorine/CYA relationship at the Pool School. Quote Link to comment Share on other sites More sharing options...
Joe L Posted May 4, 2009 Author Report Share Posted May 4, 2009 Thank you for the link, I don't have the pool open yet (I will this month as our season starts) but I will keep a better eye on the stabilizer level. Actually there seems to be a wealth of info there, thanks. Bear with me. Are you saying that because of more sunlight going through the clear cover, the extra UV's are killing more FC, so I add more pucks to replace that, and I'm just chasing my tail as that increases the stabilizer but reduces the FC efficiency. So what I should be doing, along with better testing, is to add more non-stabilized chlorine (such as bleach) so I don't increase the CYA levels too high? Rather than just tossing an extra puck in the skimmer. JL Quote Link to comment Share on other sites More sharing options...
chem geek Posted May 4, 2009 Report Share Posted May 4, 2009 There are two possible effects. One is that more UV got through the clear cover so broke down more chlorine and that caused a higher chlorine usage. If you get yourself a FAS-DPD test kit then you could measure the overnight vs. daytime FC drop to see if sunlight through the clear cover is truly the cause. Get yourself a good test kit, either the Taylor K-2006 you can get at a good online price here or the TF100 from tftestkits.net here. With a FAS-DPD chlorine test, you can measure FC and CC to within 0.2 ppm and measure up to 50 ppm. The other possibility is that your CYA level has climbed to the point where at the same FC level algae is starting to grow which results in a higher chlorine consumption even before the algae is visible (though the water might start to turn dull). The sunlight going through the cover would let algae grow more quickly if the FC/CYA ratio wasn't high enough. Quote Link to comment Share on other sites More sharing options...
Joe L Posted May 4, 2009 Author Report Share Posted May 4, 2009 Yes I realized that I'm gonna need a better kit than the basic OTO - PH and test strips that I've been using. I ordered the TF kit last night , only to find out that they canceled my order cause they don't ship to Canada. I'll check out the other link, I don't see any shipping stipulations and the pricing is better. Might though be better in the long run to find a Canadian supplier, as depending on the shipping company they tend to charge bogus 'clearing customs' fees even though there is no actual duty on the product. UPS is the worst here, Fed Ex & USPS a lot better. Thanks for the tips. JL Quote Link to comment Share on other sites More sharing options...
chem geek Posted May 5, 2009 Report Share Posted May 5, 2009 You can get the test kit in Canada here from Apollo Pools, but it's not cheap. Apparently there is a single master distributor in Canada for Taylor kits. Apollo used to offer a free magnetic stirrer with the K-2006 kit so you might ask them about that. Quote Link to comment Share on other sites More sharing options...
Joe L Posted May 6, 2009 Author Report Share Posted May 6, 2009 You can get the test kit in Canada here from Apollo Pools, but it's not cheap. Apparently there is a single master distributor in Canada for Taylor kits. Apollo used to offer a free magnetic stirrer with the K-2006 kit so you might ask them about that. Hmm, my reply for this didn't post, I'll go again. Found a supplier (PoolCenter.com) that does ship to Canada, and the k-2006 was $59.90, one of the better prices I'd seen online. Shipping a little pricey, but so far the best deal I could find. What I didn't 'get' is the pricing (before shipping ) from Apollo was $144 cad, which is over double the cost considering the exchange rate right now is; $1.17cad = $1usd. That's a common thing here in that we really do have to do our homework as many products (esp pool related) don't reflect the exchange rate and seem to be gouging. It's not the actual cost most the time, but I really don't like supporting business' that do this. I'm also a musician, and there is wild pricing variations in that industry as well. Some local dealers are actually better than the US price when factoring in exchange, but you can't assume anything and usually have to check. Again, thanks for your help. I've been reading quite a bit of previous posts (here and as well in TFP) and I'm getting a sense that it's gonna be a good season this year with me 'upping' my pool chemistry IQ. I really do see that I've been relying way too much on the stabilized pucks. JL Quote Link to comment Share on other sites More sharing options...
chem geek Posted May 7, 2009 Report Share Posted May 7, 2009 I'm surprised the poolcenter.com will ship the Taylor kits to Canada. Supposedly, the deal with the distributor in Canada for Taylor is exclusive. Cross your fingers... Quote Link to comment Share on other sites More sharing options...
Joe L Posted May 7, 2009 Author Report Share Posted May 7, 2009 I'm surprised the poolcenter.com will ship the Taylor kits to Canada. Supposedly, the deal with the distributor in Canada for Taylor is exclusive. Cross your fingers... Sometimes it just depends on the sales guy you get. I usually do check the FAQ's, shipping, policy pages though pretty quick if I see something with a good price. And I didn't see anything about Canada on their site, just a note about international orders, and there wasn't any exclusions that I recall. So I phoned them and it did take a while though to figure out the shipping cost. Btw, probably should hijack the thread too much, but I've read a lot about the CYA being diluted by rainwater, seasonal refilling, and topping up due to filter backwashing, evaporation,, etc. That all fits me as I'm in a northern climate that freezes and I also use a sand filter. This started me thinking about rainwater again. But (getting to the question in a long way) after talking to a local pool co who installed a new liner a while back, I asked if I should utilize the melted snow from my winter cover, or rainwater off a nearby garage and he said that I'd have tons of chemical problems using that water. Is it a good idea to use any collected rainwater, or just use tap water for any topping up? Of course when I get my kit I'll do some tests on some rainwater I collect in a basin for the garden, but there might be minerals I can't test for as well. Opinions? TIA. JL Quote Link to comment Share on other sites More sharing options...
PaulR Posted May 7, 2009 Report Share Posted May 7, 2009 I used my kit to test rainwater once. pH was low, but TA and CH read zero. Obviously couldn't test for other minerals, but I wouldn't think straight rainwater (or snow on the cover) would be any problem. Runoff from a roof or driveway, now, that could pick up stuff you don't want in the pool. --paulr Quote Link to comment Share on other sites More sharing options...
chem geek Posted May 7, 2009 Report Share Posted May 7, 2009 JL, I use rainwater over the winter to dilute my pool water and haven't found any problems. In my case, the rain water is coming from the pool cover (via a pool cover pump) so isn't even that "pure" since leaves and stuff are on the cover. I don't think you'll have problems using rain water. The one item in your list for CYA dilution isn't true: evaporation. Evaporation only removes water and nothing else. So evaporation and refill will not remove anything from the pool water and will add whatever is in the fill water to the pool (usually TA and CH). Richard Quote Link to comment Share on other sites More sharing options...
Joe L Posted May 9, 2009 Author Report Share Posted May 9, 2009 The one item in your list for CYA dilution isn't true: evaporation. Evaporation only removes water and nothing else. So evaporation and refill will not remove anything from the pool water and will add whatever is in the fill water to the pool (usually TA and CH). Richard Yeah I know, I worded that wrong. I was just commenting on the reasons for topping up, as none of them exist in isolation. Also I wasn't thinking of the rainwater picking up possible nasty chemicals or whatever from the shingles, good point. So I guess that idea is out. Just trying to be more efficient with the resources I already have. Again, thanks for all the comments and sharing of knowledge. Once I get my new test kit and try some of the tips I'm sure it's gonna be a far better season. JL Quote Link to comment Share on other sites More sharing options...
Joe L Posted July 7, 2009 Author Report Share Posted July 7, 2009 Just so you know Richard, it was low cya levels. Very low. JL Quote Link to comment Share on other sites More sharing options...
PaulR Posted July 14, 2009 Report Share Posted July 14, 2009 Although... as the original question related to covers... On another forum, somebody mentioned she had just gotten a new cover that was much darker than the previous one, and noticed less FC loss. This was especially obvious when she went on vacation for a week; brought the pool up to shock level, maybe 16 or so, and when she got back the FC was still something like 8. --paulr Quote Link to comment Share on other sites More sharing options...
Joe L Posted July 17, 2009 Author Report Share Posted July 17, 2009 Although... as the original question related to covers... On another forum, somebody mentioned she had just gotten a new cover that was much darker than the previous one, and noticed less FC loss. This was especially obvious when she went on vacation for a week; brought the pool up to shock level, maybe 16 or so, and when she got back the FC was still something like 8. --paulr Well yes as far as the original question, it's hard to compare as I wasn't testing cya myself before. So FC levels wouldn't mean a lot. And the FC levels do seem to be consistent now that I've got things above 30ppm cya. As far as the trichlor pucks being suspect? That's still a possibility as I've been still using them a bit, but the cya has been constant except for when adding granular cya. So while I can't say for sure about the cover being worse, it wasn't my problem ultimately. But it would be nice to see any data-spec's from the cover makers on this. JL Quote Link to comment Share on other sites More sharing options...
Bugman1400 Posted July 17, 2009 Report Share Posted July 17, 2009 Does the CYA level decrease over time without dilution? If so, how long does this typically take? Quote Link to comment Share on other sites More sharing options...
chem geek Posted July 17, 2009 Report Share Posted July 17, 2009 Does the CYA level decrease over time without dilution? If so, how long does this typically take? Basically no, though there is a very slow oxidation of CYA by chlorine that over many months could be seen as a slow drop in CYA. However, this effect is usually masked by a drop in CYA from splash-out, rain overflow or backwashing (i.e. regular water dilution). Evaporation and refill does not change the CYA level since only the water evaporates so this just increases levels in the water with whatever is in the fill water (usually TA and CH, but there is zero CYA in fill water). If the chlorine level drops to near zero for at least a day or so, then bacteria can convert CYA into ammonia, but this is not regular nor predictably reliable. Usually, getting the chlorine to zero just results in algae growth and/or growth of bacteria that don't consume CYA. Quote Link to comment Share on other sites More sharing options...
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