We would appreciate to receive your comments on the way we operate our pools, particularly the club pools. We are learning a lot in this site and that is a good opportunity to demonstrate our gratitude for that wonderful assistance.
Our experience is that the key product to a healthy pool is bleach and the focal point to treat is the filter, since the filter area is more than one thousand the poolâ€™s area. There are many possibilities to form colonies of algae, bacteria and other microbes in the volume of the sand inside the filter. And the quick way the algae growth in the pool when the chlorine goes to zero ppm, even when we treat the filter sand with bleach, is an evidence that they are still there.
We treat our club pools with bleach, supplemented with baking soda, chlorine acid, calcium chloride, sodium and cyanuric acid, the last under the form of dichlor. Before the presence of CYA we used sodium bisulfite when the chlorine was 5 ppm or over. Now we donÂ´t consider necessary to limit the chlorine to 4 ppm.
The addition of bleach is done each day only at night, after we finish all activity, with the intention to have not TC higher than actual during the period of the use of the pool and, additionally, give a small shock. Although we have diaphragm pumps, additionally we opt to concentrate the treatment ounce daily at night to have a minor shock each night. Additionally, in the middle of the week, during the lunch period, we treat each filter with bleach (added in the pre-filter), kept into the filters during 30 minutes and, backwash the filers to the sewage.
We backwash the filters to the sewage two times per week and our preference is Monday and Friday. The water consumption is 6% of the volume of the pools per week, substantially with backwash and swimmerÂ´s carried out. This means that the turnover water inventory is approximately 17 weeks or four months. We use this date to estimate the CYA content and calculate the dichlor to be add to stay between 10 and 20 ppm. We did not measure the CYA content. Our intention with this level is cut the presence of trichloramine by 50% and HClO by more than 90%, avoiding higher number because the impact in the shock level necessary to kill Bill.
We maintain the TC between 2 and 4 during the day , but TC goes to 6 after addition of bleach at night, pH at 7.6, TA between 80 and 120, CH above 250 and CYA between 10 and 20 ppm. The average consumption of chlorine in the club pools is 3 ppm per day. Before the treatment of the filters with bleach the average consumption of chlorine in the club pools was 5 ppm per day. The daily average frequency at the two principal pools is over 100 person per pool, from Monday to Saturday (at midday).
We use TC and not FC in order to simplify the frequent analysis and because we donÂ´t have easy access to FC kit analysis. We measure the FC when we are trying to reduce the chloramines, as in the case of UV treatment.
The temperature of the two larger club pools is maintained between 86Âº F and 88Âº F and, the others two between 90Âº F and 92Âº F (hydrotherapy). The private pool is not heated and its temperature is estimated around 77ÂºF.
We use oxalic acid to clean the borders of the pools and the deposits, probably ferrous compound. Calcium chloride is used to precipitate calcium oxalate. In the process the pools became turbid and we backwash to the sewage, accelerating the process by adding clarifier into the pools. Weekly, at Saturday, we shock the pools, doubling the addition of bleach soda.
We try to maintain in our club poolÂ´s a dynamic (measured at the entrance of the water in the pools) ORP minimum of 700 mv. We are now adding a UV in the 12000 gal pool, trying to reduce the chloramines presence during the day. The experience with UV is small (some days) but shows a reduction in the chlorine consumption and consequently reduction in the chloramines production. We tried hydrogen peroxide but this compound destroyed very quickly the HClO and gave us an headache with immediately growth of algae. We are using the CYA in the indoor pools with the purpose to reduce the complains about the irritation of eyes and skin with great success (we believe through the reduction of HClO and trichloramine). Apart from that, we maintain a air exhaustion system with a minimum capacity of six times the volume of the airspace pool. We use filter bag with 1mm mesh (when new) to reduce the amount of skin and other particles present into the pools - the bag filter is in parallel to the sand filter.
In our private pool we use calcium hypochlorite and we add only one time per week through the skimmer, using around 7 ounces per week. In this pool the TC varies between 10 (after we add hypo) and 5 (just before). Interesting is that when we introduce the practice of deep treating the filter with concentrated hypo, the consumption of chlorine drop to 1 ppm per day that is approximately the number that you mention that Janet (user name Aylad) obtained using 80-90 CYA. But we are using between 10 and 20 ppm of CYA. This pool receives directly sun light during 50% of the day. After we introduce the filter treatment with bleach we eliminate the brush since there is no more presence of algae. It is necessary only clean the debris in the bottom of the pool and clean the borders with oxalic acid.
1) 40000 gal indoor ceramic club pool, 50Â´x 25Â´,2HP, sand filter, bag filter, 5 HP titanium heat pump.
2) 12000 gal indoor ceramic club pool, 26Â´x 16Â´,3/4HP sand filter, bag filter,5 HP titanium heat pump.
3) 4000 gal indoor ceramic club pool, 12Â´x 10Â´, 1/2 HP sand filter, 5 HP titanium heat pump.
4) 2000 gal indoor ceramic club pool, 9Â´x 6Â´,1/4 HP, sand filter, electrical resistance heater.
5) 6000 gal outdoor ceramic private pool, 24Â´x 10Â´, 1/2HP, sand filter.