polyvue

Thanks for the kudos but I'm just an actor... I didn't write the play. From the time I started researching pools in 2007 I read everything I could (my build was May-August 2007) from every source on the net. I learned the most from Pool Solutions / Pool Forum but found posts from waterbear, chem geek and others in this forum and TFP that answered questions I had about pool chemistry - questions that in some cases were not even being asked in forums that were more tightly coupled with pool products and services. That's why my loyalty, such that it is, goes to independent web sites. My recommendation to target a FC level of ~ 5% of CYA is just a rule of thumb. is derived from this Chlorine/CYA Chart, and applies to pools chlorinated with SWGs and other automated devices. I don't consider any of this gospel or dogma. If it doesn't work, question it...

I have seen this myself. However, when double checked with a chromate/silver nitrate titration the results have been more in line with the strips (since both are using silver nitrate to test for chloride ions) and not with the conductivity tests. I have also had the experience of hand held meters showing the same ballpark results as the SWG itself while a chemical test shows a much higher value. This is because you are trying to compare apples and oranges (conductivity and cloride ion concentration.) I have also seen this discrepancy to be in the ballpark of 800-1000 ppm (and Goldline even has said on their website before it was redone that their readings could be off by as much as 800 ppm compared to a chemical test.) Also realize that my experience has not just been with my own pool but also customer's pools. My experience is limited to my own pool and dates back almost 36 months -- beat that! Everything you say makes sense... but referencing my own vast 4-month comparative sampling (!) I found that once the salt test strips began showing high levels of salt (the SWG reported no change, warm summer water, no calcification or debris in the cell, 2 bottles of test strips purchased a year apart from different sources agreed with each other) the only correlation was between the silver nitrate drop test and the cell. The drop test results were and remain within 100 PPM of what the cell reports. I ran out of salt strips in the fall and didn't continue the comparison but the results of a conductivity test using a salt/tds meter in October were in sync with the cell and the drop tests. Go figure. If you have some inkling of what may have contributed to this experience I'm all ears.

Be careful here. Six (6) gallons of 10% bleach seems like too much chlorine (1 gallon = 128 oz. 6 * 128 = 768 ounces). Adding 768 ounces of 10% bleach to an 8000 gallon pool will increase Free Chlorine by ~ 75 PPM (this assumes that the 10% bleach is fresh and full strength). That's an appropriate shock value if the pool has 160-200 PPM Cyanuric Acid (CYA). But if CYA is that high, you're better off draining 2/3 of the water before you begin to shock. If CYA is in the more typical range of 40-50 PPM, using only 1.5 gallons of 10% chlorine is sufficient; it will raise FC by 20 PPM.

I agree with your conclusion. It's the SWG cell's report that matters for chlorine production. I'm sure some folks have used expired AquaChek/Hach salt strips or removed the desicant, left them open, etc. but I was able to rule out each of these issues and still had a huge discrepancy to account for. On the Hach website I found a number of reasons provided by the manufacturer (possible interferences) but half of them didn't seem to apply and the others required testing facilities I lacked. My problems with the test strips drove me to start researching TDS constituents, thinking that there was something in the water that was tweaking the salt strips (and causing the same manufacturer's strips to report 6000+ PPM TDS). I have to say that this was not a fruitful pursuit. It's possible, to the degree that anything is possible, that the pool water contained an unusual element that caused both strip tests to read high but I've given up searching for it. For what it's worth, a few other reg contributors to that forum reported similarly high levels of salt (chloride) when using test strips, much higher than the conductivity measurements of their SWGs would suggest.

Gavin, read through the advice given to aGrandma in the last couple of days about the best way to kill algae. I don't know how large the pool is so can't advise on how many gallons. To shock for algae, go all the way up to shock level (usually 40% of CYA is sufficient) and don't let it come down for several days, pumping/filtering the entire time. You only need to backwash the filter if the pressure has risen 8 to 10 PSI over normal. And brushing never hurt anything (except biofilms and algae cell walls!) and could help.

What Mark said. It's good that you're investigating places the algae can hide (the green and black scum is probably algae) and cleaning these areas; keep an eye on your filter and hose off the cartridges when necessary (or backwash, if you have a DE or sand filter) --- but the most important thing you can do is to get the chlorine up to a high level and KEEP it there, constantly filtering.

I have an above ground pool but I don't know how much shock to use. It's 24 ft and I'm not sure of how many gallon it holds. We have some algae, but with a weekly cleaning it usually goes away. Should I be using shock? Welcome to the forum. If your pool is round 24' diameter with a depth of 48", it holds approximately 13,500 gallons of water. If you have recurring algae either your daily Free Chlorine (FC) level is insufficient (try to maintain a minimum FC of 7-8% of CYA at all times) or the weekly cleaning (shocking?) is not removing the algae completely, or both. Example: If the Cyanuric Acid (aka CYA, stabilizer or conditioner) in your pool is 50 PPM, shoot for a minimum FC of 3.5 PPM. If you don't have enough CYA (< 20 PPM) then it's likely the chlorine is burning off too quickly during the day and that will increase your exposure to algae problems because your chlorine is being depleted. How do you normally chlorinate the water (which product)?

You're aiming for a shock level of 32 PPM Free Chlorine(FC)? For CYA = 80 this sounds about right. The trick to successful shocking is to very quickly raise the Free Chlorine to shock level (in other words, have enough bleach or liquid chlorine on hand and add it all at once) and then HOLD it at that level for several days or until there is no more than a 1 PPM loss of chlorine from evening until early morning, and the pool is crystal clear. This often means testing several times a day (much easier when you have your own test kit) and adding chlorine through-out the day as needed to maintain the 32 PPM. If you try to cheat this procedure (let it go for a day or two), the algae may re-group and you'll be fighting this all summer. Keep the pump running all day and all night, brush the sides and floor of the pool and clean out skimmer/pump baskets at least once a day, and clean/backwash your filter when the pressure climbs to 10 PSI over normal. Read through Defeating Algae and see if this doesn't make sense in your situation. Post back with questions. Many folks here have gone through this tunnel and emerged unscathed from the other side.

Zero chlorine? Though you may have only noticed algae on the boulders, it seems that you have the beginning of an algae bloom in the pool. I would recommend that you adjust your pH from 7.8 down to 7.0-7.4 with muriatic acid and commence shocking for algae with liquid chlorine or 6% bleach. Use one of the following tables to determine the right amount of chlorine to shock with (it's based on CYA/stabilizer): Best Guess CYA Chart Chlorine CYA Chart For your pool (CYA 40 PPM) a shock level of about 15 or 16 PPM should work. A bit more will just speed things up. The best way to successfully shock is to quickly add the full amount of chlorine needed and then HOLD it at that level while pumping/filtering 24/7 until the algae is gone and the water is crystal clear. If you're able to test Free Chlorine (FC) and add more chlorine to restore it to shock level several times a day, it shouldn't take long to get rid of it. You know that you're finished when your early morning FC is no more than 1 PPM less than nighttime FC. During this time, keep an eye on your filter and backwash (sand or DE) or clean (cartridge) when the pressure increases 10 PSI over normal. Keep skimmer/pump baskets cleaned out and brush pool walls (and boulders!) daily or more often. More is explained here.

Yes, but... the solar panels contribute to pressure-side head. So, as you said, if there is enough power to get it started -- i.e., if the pump can prime and push water into the empty solar array (may require high speed to accomplish this) then it should be able to maintain that pressure at a lower speed.

Assume this is an in-ground plaster or pebble pool. How many gallons? How long is the pump/filter operated each day? Is the pool cloudy or clear? Finally, could you post the most recent test results? pH Free Chlorine (FC) Combine Chlorine (CC) Total Chlorine (TC) Total Alkalinity (TA) Calcium Hardness (CH) Cyanuric Acid (CYA or stabilizer) Salt PPM For resolving an algae problem, the most important factors are Free Chlorine and CYA in PPM. If your SWG and filter are working properly and you have been maintaining a Free Chlorine level of 5% or more of CYA, there's less opportunity for an outbreak. E.g. If your CYA is 50 PPM, you'd want a minimum Free Chlorine level of 2.5 PPM. Another thing that might help is regularly brushing the boulders in the area where they are getting algae along with your pool.

You could employ a couple of chlorine tab floaters (with TriChlor tabs) in the pool but be careful that they don't come to rest in one place --- move them around throughout the day and continue to stir the water with a leaf rake or broom. Continue to test the water to be sure pH doesn't get too low or too high (somewhere between 7 and 8 is OK).

My perspective is that there is no such thing here as the "right" answer. If you're testing regularly, especially pH, Free Chlorine and CYA, and can maintain a minimum Free Chlorine level of 7 or 8% of CYA through the use of TriChlor or DiChlor... and don't mind draining some water from the pool on occasion when the CYA reachs intolerable levels (say over 70 or 80 PPM, when shocking becomes problematic due to an elevated need for chlorine) then you may be a candidate for using stabilized chlorine. This will be easier to achieve if you have a sand or DE filter (because backwashing removes water from the pool) and have a heavy bather load (more water loss due to splash out). If you use stabilized products exclusively you must understand that for every 10 PPM of chlorine (5 days in your pool?) added by these products, 6 - 9 PPM of cyanuric acid is also added to the pool. The chlorine gets used up, the CYA stays in the pool and doesn't dissipate through evaporation. So, with a current CYA level of ~30 PPM, how long might it take to reach 80 PPM? A month or two? So there's the issue.

Very nice setup... love that you've color-matched the spa's cover to your house color. But what's with the canopy? The best thing about soaking for me is the time I get to spend star-gazing.

But I am still afraid to add gallons of bleach to my pool! I've never done it before....When will the pool be safe to swim in again? There's a bit of a trade-off regarding swimming. I wouldn't want to swim in a pool that is being shocked for algae but once it is cleared up (usually in a few days) you can swim all summer -- assuming, of course, that you continue to maintain sufficient chlorine levels. Don't be worried about the gallons of bleach needed to reach and hold shock level; once it is in the water it becomes Hypochlorous acid - the same stuff that's generated by your SWG. After I get the chlorine level way up (shock), will I then have to add a bunch of additional chemicals to balance the water again - will it get all out-of-whack or will it be easy to get it under control again? There may be an initial rise in pH --- that's one reason why you will want to adjust pH down to 7.0-7.5 before shocking -- but it will come down again as the chlorine does its work. You won't have to add a bunch of chemicals to balance the water again if the water started off balanced. What I'm wondering is, how much is this going to cost me....in trips to the pool store, in chemicals, etc. Invest in a good test kit (one-time purchase) and you will not have to keep visiting the pool store for testing. If your pool store carries 12.5% liquid chlorine ("pool chlorine") at a reasonable price you can use this to shock -- or just buy unscented regular or ultra bleach (active ingredient: 6% sodium hypochlorite). So..... $60 or less for a good test kit and however many jugs of chlorine it takes to clear the pool. If you compare this expenditure against the dollars you'd spend buying unneeded chemicals and powdered shock over the summer, you'll be saving money. If you need to lower pH, don't use pool store products such as "pH down" -- save money by purchasing Muriatic Acid 33.45% -- many pool stores carry this, as do hardware stores. In my state, even grocery stores carry muriatic acid. Also, how do I add the bleach? Do I walk around the perimeter of the pool and slowly pour evenly or does it even matter? Do I add it near the filter input? Best way to add bleach (first, determine how much you want to add -- x number of gallons or jugs etc.) and then pour each jug in slowly away from the pool wall and in front of a return (the jets that return filtered water to your pool). If you have a return in the deep end, that's preferable. Keep the pool pump/filter running the entire time you're adding any chemical and for at least an hour afterward. In my pool I divert suction to 100% main drain to accomplish this quickly, but it's not a requirement. I don't recommend adding liquid chlorine/bleach to a skimmer.

Really need full test results to proceed. Here's why: It could be that you have copper in the water (do you have a heater? have you added copper-based algaecides in the past year?) or the rusty brown stuff in the filter could be dead or not-so-dead algae. An effective chlorine level depends on the amount of cyanuric acid (aka CYA, stabilizer, conditioner) and the chlorine tablets may be exacerbating a too-high CYA issue -- if the composition is Trichlor or Dichlor they're adding 6-9 PPM CYA to the water for every 10 PPM chlorine. Strongly recommend that you procure a good test kit (such as the Taylor K-2006 or equivalent) so you can definitively measure CYA. Pool stores are rather notorious for mis-measuring CYA so relying on their testing accumen may just lead to confusion. If your testing (or the pool store test) has determined that pH is 8.0 you should take immediate steps to reduce it via muriatic acid. That's because the typical phenol-red test for pH tops out at 8.0 so you may have pH that's much higher than that. You can determine how much muriatic acid is needed by using the Pool Calculator - but I would suggest that you only add one-half of the recommended dose and re-test after a few hours of pumping before adding more.

It's possible you have several problems (algae, diagnosing the noisy pump, filter media) but I would focus first on pool chemistry. Invest in a good test kit (such as the Taylor Complete (FAS-DPD Chlorine) available for less than $50 here) and post back numbers for pH Free Chlorine (FC) Combine Chlorine (CC) Total Chlorine (TC) Total Alkalinity (TA) Calcium Hardness (CH) Cyanuric Acid (CYA or stabilizer) Clarifiers and flocculents aren't going to kill algae, of course, and they may not be needed at all. I would proceed with the assumption that there is still some live algae in the pool and go from there. Using liquid chlorine (not powdered shock) gives you the best chance to clear the pool. You want to know the CYA level exactly and begin dosing the pool with liquid chlorine or bleach until the algae is killed. This process is explained in some detail here. It's possible to clear the pool without the test kit but it is a whole lot easier (and faster) to do it yourself.

I have a salt pool and have used Genesis shock (powdered Trichlor) on occasion, but if I had an algae problem (or high CYA) I would cease using it and use only liquid chlorine (10-12% or 6% bleach) to combat the green monster. Read the articles linked by chem geek (above) and prepare to buy a good amount of bleach or liquid chlorine. Do you have a good test kit? To defeat algae while relying on a pool store to conduct your tests is difficult because you'll be needing test results several times a day.... Recommend purchase of the Taylor K-2006 Complete FAS-DPD Chlorine kit, available from a number of vendors for less than $60.00: Amatoind.com Poolcenter.com Spspools-spas.com For whatever reason, brick and mortar pool stores don't carry this kit. Once you have your test kit, test for Cyanuric Acid (CYA, stabilizer) and then determine the right level of chlorine for shocking*. You can use the Pool Calculator to determine how much chlorine to add. The main idea (and this is explained in the links provided by chem geek) is to quickly escalate the level of chlorine in the pool and then HOLD it there, pumping 24/7 until the water clears or an overnight chlorine loss test shows less than 1 PPM chlorine lost from dusk to dawn. You will be testing several times a day and adding chlorine as needed to maintain this high level. * If CYA > 80 PPM the sensible course is to drain some of the pool water and refill so you can start at a reasonable baseline.

Sounds great. I was just wondering if you have a way to backwash the sand filter once the pressure starts rising. But perhaps you've already got that figured out.

Wrong dimension. 18 feet is most assuredly the pool's diameter.

A 98-degree pool? Where do you live, Equador? Assuming that this is not just a large spa but a pool that contains many thousands of gallons of water, this will be expensive (to say the least) to maintain. I hope you plan on keeping it covered when you're not swimming. The so-called Natural systems often dose the pool with minerals (silver, copper) and you have only to read up on the problems of sanitation and staining with these systems - in this forum and others - and you will be dissuaded from this approach.

$999.89 at the link you posted.

I'd recommend keeping the pool filled if at all possible. I don't know the pricing typical for fixing leaks in a liner pool, but none of the numbers you posted seem alarming... let them do the additional testing so they can fix it right the first time. If you insist on telling them what to fix and you have missed a leak, you haven't fixed the problem but have given the company reason to charge more for coming out a second time.

Welcome to the forum. What type of pool (in-ground or above-ground, vinyl, fiberglass, gunite, etc.) What product are you using to chlorinate with? Please be more specific about your chlorine and pH level. Post any test results you have for pH Free Chlorine (FC) Combined Chlorine (CC) Total Chlorine (TC) Total Alkalinity (TA) Calcium Hardness (CH) Cyanuric Acid (CYA or stabilizer) Clearing an algae bloom is not difficult but may take a few days. Adjust pH to low to mid-range, say 7.0 to 7.5 ppm, then increase FC to shock level (see the Best Guess CYA chart) quickly and hold it there until the pool clears or you have less than 1 PPM chlorine lost between dusk and dawn. A common reason for algae outbreaks is water that has been over-stablized through the use of Tri-Chlor or Di-Chlor compounds so that the chlorine level is insufficient to kill the algea. But since you just filled the pool, that's unlikely. Post back some numbers and we should be able to help you fix the problem.

The pool isn't that small.... about 400 sq ft and 16,000 gallons if the floor is 5.5 ft deep throughout. You didn't mention the model number, but both the CCP420 or CCP520 should provide sufficient filtering. When you clean the cartridge filter what do you see? Are there pine needles or mud/silt or other debris that you wash out of the cartridges? Plaster dust? Is the pool vacuumed regularly... skimmer basket(s) and pump baskets cleaned out at least once a week? Lots of trees in your area? Just trying, as you are, to figure out what could be causing your filter to need cleaing so often. The next thing I would look at is pool chemistry (pH, FC, CC, TC, TA, CH and CYA) and plumbing.