I'm getting RO done this week

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zea3 said:
Once they are finished you will need to re-balance the pool. RO is great for getting rid of excess calcium and CYA, but it is not offered in enough locations for it to be a replacement for drain and refill in most cases. In an area with inexpensive water and no use restrictions a drain and refill will be quicker and more cost effective.

I have heard that RO companies will not process algae filled water. Do you know if this is true of the company you are working with as well?
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Yeah, Tucson Water just started adding a tiered charge system for the "service charge" portion of the bill. The usage rate was always tiered but the service charge was static - you paid $20 per month for your account whether you used water or not. Now they have both the flat service fee AND an additional service fee based on a tiered rate for water consumption. It's totally ridiculous and adds a lot to the monthly bill. So previously drain and fill was right on par with RO but now it would be a lot more expensive to drain and fill.

As for algae I would believe it because the pre filter sediment traps will clog up like crazy. If/when I do RO, I'll schedule it for the fall after the water temps drop and algae is less of a danger.
 
Originally a Taylor 2006. Added speed stir. Taylor salt strips.

The issue with a drain and refill is that the tao water is so hard. Ideally I could fill with softened water, but even with an aggressive manual regeneration schedule, it would take me at least 8 days to fill the pool. Too long out here in the heat with no one at home most days.

They did say they wont treat pools with algae. The tech did ask if I wanted him to bring any levels back up, I said I'd handle it.
 
Water CH was 350 Sunday mid day. Tonight Monday at 6p it was 220. We are going to give it one more night. I shut off the fill water to regen the softener again, and will start the fill again in 2 hours when it's ready. Gonna test in the am before I leave and shut it down if it's around 180.
 
Tested this morning and it was 150, so I shut it off. They are going to pick it up today.

I regen'd the softener last night, it started up at 1120 gallons on the meter at 11pm. I turned the autofill and hose on. This morning at 6am, water in pool was about the same level, and the meter on the softener was down to 450. So I figure I used about 100 gallons an hour overnight keeping pace with the RO machine. Which, if the machine has been running 24 hours a day since thursday afternoon, and 100 gallons an hour average, puts my at about 10,800 gallons, which is like the exact volume of my pool.

So best I can figure....I've essentially just replaced the entire volume of my pool with fresh water. Which I could have done without an RO machine albeit, with exposed pebble and a few more days of nursing the softener.

But, it seems their claim of only using 15% waste water is wildly off the mark. I don't know if high salt levels slowed the process of if their RO flush timer is too short.

Will get full slate of readings tonight.
 
TDS and temperature have a big impact on RO efficiency. If you had both high salt and high calcium, then your TDS is quite high which means the RO membrane will work less efficiently. Also, in many whole-house RO systems, calcium sequestering chemicals are injected into the input water stream to keep calcium from scaling on the RO membranes and causing them to stop working. The anti-scale chemical (typically a phosphonate anti-scale compound) is injected into the input stream and then it simply goes out into the waste stream. The high concentration of sequestering agent keeps the calcium in solution and off the membranes.

So, my guess is that your high CH probably scaled their membranes and lowered the efficiency of the process. They can clean their membranes to remove the scale but they should use an anti-scale chemical in their process if they are not doing so to reduce cycle times....but then again, if they charge you more for longer run times, then scaling is their friend ;)
 
A properly designed RO system has to take into account the TDS of the water being treated. When TDS is high, there are different selections of membranes that one can use as well as cascading multiple membranes and adding pre-filtering. Your biggest contributors to TDS are calcium and salt. CH is the problematic one because it will scale and foul the RO membrane. CYA will simply just pass through to the waste stream.

I suspect these portable RO units are not the best they can be. As well, I believe AquaLabz is the distributor/developer of these portable systems and they license their use out to local service companies kind of like how PebbleTec licenses it's plaster surfacing materials and techniques out to local plastering companies. So the person running these filtering units is probably not intimately familiar with the intricacies of the RO process.

I'm interested to see what your final numbers come out to be. A cost analysis and comparison with straight water replacement would be of interest too. My CH is up over 900ppm now so I need to start doing something. I have a very large flat roof and so one of my ideas is to install a series of rainwater harvesting tanks around my home and use them mostly for pool fill and irrigation. If I can exchange 20% of my pool water each year with rain water, then prevention becomes an option for calcium control as opposed to paying for it to be removed. Like you, my municipal water is stone-hard (250+ ppm in a good month) and I pay enough in water bills each month to put someone's kid through private school :crazy:
 
Well I'm sure just regular water replacement is probably cheaper than $325, considering how much water I likely used up for the RO anyway. But the fact that I have to recharge my softener every 1100 gallons (which takes 2.5 hours) means it would take a long time/babysitting/exposed pebble.

I think I'll just do partial water replacements when CH gets to like 600. Which, if I'm doing that, along with the high salt from bleach....I might as well just use tabs and let the CYA creep up.
 
Numbers post - RO, and stagnant in sun all day:

FC. 0
CYA less than 20
pH 7.6
TA 30
CH. 150
Salt 800-900 depending on how you read the strip.

I put 3 lbs of baking soda to shoot for 50. Went to the store from cya, adding 3 lbs of that to shoot for 30. Poured in about 30oz of 10%. Put cya in two socks, hanging in the leaf rake in front of return, squeezing every 10 minutes. CSI was -0.6. Aiming for maybe -0.3 after adjustments
 

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Chris, have you considered upgrading to a dual-tank softener system? For the cost of RO, that might serve you best long term...especially if the RO cost you that much in water!

I upgraded to a dual last year so that it wouldn't tap out during top ups. Its made a huge difference, because in my system, it will just switch ver to the fresh tank automatically when the spent one goes into regen mode. Just a thought for going forward.
 
Original fill was straight tap, to expedite fill up and not start too soft with new plaster. That was 350 maybe, I forget. I also don't mix up the salt as much as I should. 3.5 years of fill up, even the softened water is 80-100 ppm I think. We'll see how well I can keep it down.
 
JoyfulNoise said:
A properly designed RO system has to take into account the TDS of the water being treated. When TDS is high, there are different selections of membranes that one can use as well as cascading multiple membranes and adding pre-filtering. Your biggest contributors to TDS are calcium and salt. CH is the problematic one because it will scale and foul the RO membrane. CYA will simply just pass through to the waste stream.

I suspect these portable RO units are not the best they can be. As well, I believe AquaLabz is the distributor/developer of these portable systems and they license their use out to local service companies kind of like how PebbleTec licenses it's plaster surfacing materials and techniques out to local plastering companies. So the person running these filtering units is probably not intimately familiar with the intricacies of the RO process.

I'm interested to see what your final numbers come out to be. A cost analysis and comparison with straight water replacement would be of interest too. My CH is up over 900ppm now so I need to start doing something. I have a very large flat roof and so one of my ideas is to install a series of rainwater harvesting tanks around my home and use them mostly for pool fill and irrigation. If I can exchange 20% of my pool water each year with rain water, then prevention becomes an option for calcium control as opposed to paying for it to be removed. Like you, my municipal water is stone-hard (250+ ppm in a good month) and I pay enough in water bills each month to put someone's kid through private school :crazy:
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i think the big truck mounted systems work quicker with a lot less waste water, if I remember correctly.
 
I have read that RO wastes about 5 gallons of water for every pure gallon of water produced (this seems to be common knowledge and is all over the Internet). This number is about average and varies a bit up or down. Given the excessive water waste with RO, could someone explain why replacing a pool's water with RO would be preferable to draining and refilling the pool?
 
spoonman said:
I have read that RO wastes about 5 gallons of water for every pure gallon of water produced (this seems to be common knowledge and is all over the Internet). This number is about average and varies a bit up or down. Given the excessive water waste with RO, could someone explain why replacing a pool's water with RO would be preferable to draining and refilling the pool?
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That's only true for the very inefficient, under-the-sink, household type RO units. Commercial grade RO systems use high pressure pumps and membranes to boost the input pressure up to several hundred psi. In those systems, RO will only have a waste fraction of about 10%, sometimes less. It also depends a lot on input TDS and temperature.
 
BuckeyeChris said:
The real reason for the RO is to get the salt level down from 5500, as ... our travertine is falling apart.
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I constantly see anecdotal statements about salt vs travertine. Can you give some details on location(s) that are suffering, age of the travertine, frequency/type of sealers used (if any), and possibly post a pic or two showing what's happening? I'd greatly appreciate it.
 
I'm not sure it's entirely the salt; some of the travertine not near the pool is exhibiting the same thing. I'll get a pic soon. The travertine was "filled"/smooth, and I think it's the filling that is falling out.

The CH is back up to 450 after a few weeks. But my test chemicals got left outside so I'm hoping the 0010 or whatever is just bad....
 

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