Since the tank is 160 gallons can I, over about a week, add 120 gallons of RO and then do the mixing thing in containers after that?
Tapwater, RO, HMA, wet/dry and plants
- Thread starter IanB
- Start date
Hi,
160 gallons that's a big tank. 700 plus litres that'll take you most of the week to produce anyway. :lol:
If you've livestock in situ (including plants, shrimp, snails, etc.) then add neat RO a little at a time say no more than 10% daily until you've added 120 gallons to the tank overall. Check the readings on your test kits and carry on until the tanks water parameters are what your aiming for. They will still be higher than the 6dgh/4kh that we've been discussing because you'll be taking some % back out as it mixes. But it'll bring the overall parameters down nice and slowly and is what lornek8 was referring to right at the beginning of this thread.
If your in a rush do two 10% changes a day, morning and evening. I'll make no bones about it there's no sound scientific basis for my recommendation just telling you what I would do based purely on experience, others may see/do things differently.
If no livestock are present then just do it as you see fit.
Chris.
160 gallons that's a big tank. 700 plus litres that'll take you most of the week to produce anyway. :lol:
If you've livestock in situ (including plants, shrimp, snails, etc.) then add neat RO a little at a time say no more than 10% daily until you've added 120 gallons to the tank overall. Check the readings on your test kits and carry on until the tanks water parameters are what your aiming for. They will still be higher than the 6dgh/4kh that we've been discussing because you'll be taking some % back out as it mixes. But it'll bring the overall parameters down nice and slowly and is what lornek8 was referring to right at the beginning of this thread.
If your in a rush do two 10% changes a day, morning and evening. I'll make no bones about it there's no sound scientific basis for my recommendation just telling you what I would do based purely on experience, others may see/do things differently.
If no livestock are present then just do it as you see fit.
Chris.
:thumbup:
Quality... thanks... I thought it sounded an ok theory but wanted to double check..
Yeah.. 700 litres for a coupla dozen plants and a Gibbiceps that is doing a great impression of a bulldozer at the moment..
Quality... thanks... I thought it sounded an ok theory but wanted to double check..
Yeah.. 700 litres for a coupla dozen plants and a Gibbiceps that is doing a great impression of a bulldozer at the moment..
It runs cold on my hot supply because... since washing machines were brought into the future with integrated heaters; they only use the cold intake leaving one spare- this runs cold as the new combi boiler isnt heating that supply (as was the previous hot water system) what with washers not needing the two inputs nowdays
Hi,
Ok I checked the TDS readings today whilst doing some routine maintenance on my RO unit and I beg to differ with you now Bob.
The TDS at my supply is 352ppm and the TDS of my reject water is 474ppm. So I now believe that its as I originally thought where the nasties end up concentrated in the reject water and not held in the membrane as you suggested.
Either that or my RO unit isn't working right. Pre DI resin 14ppm, final product water 0ppm.
Chris.
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The thick plottens.. interested to see if this is the norm or there's other factors (on either evidence).. :thumbup:
Chris
I cant explain this
I have used R/O for years never had a reading over the tap water reading.
If you follow my reasoning even if the waste water was being discharged we are talking over 100ppm Up
Mine is normaly 100 to 150 under my tap water TDS
I just checked it !!?? seems strange all toyr readings at the product water end are as I would expect.
My I ask do you flush your membrane? I flush mine every 15 mins foor 30 secs, I have a RO man auto flush.
Be interesting to check the water before the membrane and after the carbon Block?
Hi Bob,
Yes I flush the membrane regularly although not as regularly as you. I tend to run RO off once or twice a week as I have a 50 gallon holding tank and it takes all day to fill this. So what I normally do is to flush the membrane for 5-10 minutes before filling commences. This is done at least once a week which is as per manufacturers recommendations.
The TDS yesterday of the pre membrane was 348ppm, which I'll admit I thought was a bit high. But my water is very hard and seeing as its mostly the gh and kh that remains unaffected by the pre filtration stages I consoled myself that the supply water must be otherwise quite clean.
Both the carbon filter and the sediment filter are about 5 months old so may be coming to the end of there useful life, but then that shouldn't make a huge difference there not exactly 'old'.
I have a 100 gallon per day 4 stage system with a booster pump to increase the pressure to 80psi. The membrane is coupled with a 3:1 flow restrictor.
Chris.
Yes I flush the membrane regularly although not as regularly as you. I tend to run RO off once or twice a week as I have a 50 gallon holding tank and it takes all day to fill this. So what I normally do is to flush the membrane for 5-10 minutes before filling commences. This is done at least once a week which is as per manufacturers recommendations.
The TDS yesterday of the pre membrane was 348ppm, which I'll admit I thought was a bit high. But my water is very hard and seeing as its mostly the gh and kh that remains unaffected by the pre filtration stages I consoled myself that the supply water must be otherwise quite clean.
Both the carbon filter and the sediment filter are about 5 months old so may be coming to the end of there useful life, but then that shouldn't make a huge difference there not exactly 'old'.
I have a 100 gallon per day 4 stage system with a booster pump to increase the pressure to 80psi. The membrane is coupled with a 3:1 flow restrictor.
Chris.
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Hi,
I'm not lieing or making this up and its been bothering me since Sunday now, can't seem to get it out of my head for some reason.
I've been looking at a bit of math as well to help explain whats going on and I think that I have the basis of an explanation for it.
The water pre membrane was 348ppm, so just isolating the product water for a moment the fall post membrane was 334ppm i.e. 348ppm-14ppm. The flow restrictor has a ratio of 3:1 so divide this by 3= 113ppm and add to the ppm water pre membrane 348ppm + 113ppm = 461ppm. The reading that I took of the reject water was 474ppm which isn't a long way off. Its quite reasonable to expect that some allowances are made for the accuracy of the flow restrictor, membrane and TDS meter. So to my mind this all goes a long way to explaining why my reject water is so high.
I'm sure your not making it up either Bob so it appears that there's not necessarily only one way that these things work, and I'm starting to think along the lines of it depends what type of minerals are the mainstay of the ppm in the source water in the first instance as to whether the reject water will have a lower TDS reading than the source water.
Its the only explanation I can think of.
I'd be very interested in your TDS readings at all stages of the filtration process for direct comparison with mine. I'd seriously like to get to the bottom of this as if I'm doing anything wrong I'd like to rectify it and as a basic minimum I'd like a broader understanding of whats occurring.
The following snipet is copied directly from this website:-
http://www.home-water-purifiers-and-filters.com/reverse-osmosis-filter.php
Found under the sub heading "How it Works".
Reverse osmosis uses a membrane that is semi-permeable, allowing pure water to pass through it, while rejecting the contaminants that are too large to pass through the tiny pores in the membrane. Quality reverse osmosis systems use a process known as crossflow to allow the membrane to continually clean itself. As some of the fluid passes through the membrane the rest continues downstream, sweeping the rejected contaminants away from the membrane and down the drain. The process of reverse osmosis requires a driving force to push the fluid through the membrane (the pressure provided by a standard residential water system is sufficient - 40 psi+).
Therefore the membrane does not as you suggest hold onto the contaminants, which is why its very possible that the reject water can have a higher TDS than the source water.
Chris.
I'm not lieing or making this up and its been bothering me since Sunday now, can't seem to get it out of my head for some reason.
I've been looking at a bit of math as well to help explain whats going on and I think that I have the basis of an explanation for it.
The water pre membrane was 348ppm, so just isolating the product water for a moment the fall post membrane was 334ppm i.e. 348ppm-14ppm. The flow restrictor has a ratio of 3:1 so divide this by 3= 113ppm and add to the ppm water pre membrane 348ppm + 113ppm = 461ppm. The reading that I took of the reject water was 474ppm which isn't a long way off. Its quite reasonable to expect that some allowances are made for the accuracy of the flow restrictor, membrane and TDS meter. So to my mind this all goes a long way to explaining why my reject water is so high.
I'm sure your not making it up either Bob so it appears that there's not necessarily only one way that these things work, and I'm starting to think along the lines of it depends what type of minerals are the mainstay of the ppm in the source water in the first instance as to whether the reject water will have a lower TDS reading than the source water.
Its the only explanation I can think of.
I'd be very interested in your TDS readings at all stages of the filtration process for direct comparison with mine. I'd seriously like to get to the bottom of this as if I'm doing anything wrong I'd like to rectify it and as a basic minimum I'd like a broader understanding of whats occurring.
The following snipet is copied directly from this website:-
http://www.home-water-purifiers-and-filters.com/reverse-osmosis-filter.php
Found under the sub heading "How it Works".
Reverse osmosis uses a membrane that is semi-permeable, allowing pure water to pass through it, while rejecting the contaminants that are too large to pass through the tiny pores in the membrane. Quality reverse osmosis systems use a process known as crossflow to allow the membrane to continually clean itself. As some of the fluid passes through the membrane the rest continues downstream, sweeping the rejected contaminants away from the membrane and down the drain. The process of reverse osmosis requires a driving force to push the fluid through the membrane (the pressure provided by a standard residential water system is sufficient - 40 psi+).
Therefore the membrane does not as you suggest hold onto the contaminants, which is why its very possible that the reject water can have a higher TDS than the source water.
Chris.
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Hi,
YUK!!!:lol:
Ian when you get your TDS meter running will you also check and post on here the readings at the 4 main stages of water filtration. Namely source, pre-membrane (i.e. after sediment and carbon filters), reject water and product water (pre DI resin if used).
Also anyone else for that matter as I really would like to get to the bottom of this and the more data available for comparison the better.
After further thought (god I hate myself when I get obsessive about things, LOL) I'm back to thinking your right Bob with regard to using the reject water to cut back into the product water for remineralising. Even though in my case the TDS of the reject water is higher than the source water. The TDS of the reject water should consist almost entirely of gh and kh (calcium, magnesium and carbonates) albeit more concentrated than the source water and therefore higher in there respective hardness values. So you will simply need less volume wise to bring the RO water back up to the desired value than you would if using tapwater (by about a quater at a guess). Its still been filtered by both the sediment and carbon filtration so will be 'cleaner' of the minerals that they extract.
I'm also starting to doubt the effectiveness of my carbon/sediment filters and will be changing them a.s.a.p.
Chris.
YUK!!!:lol:
Ian when you get your TDS meter running will you also check and post on here the readings at the 4 main stages of water filtration. Namely source, pre-membrane (i.e. after sediment and carbon filters), reject water and product water (pre DI resin if used).
Also anyone else for that matter as I really would like to get to the bottom of this and the more data available for comparison the better.
After further thought (god I hate myself when I get obsessive about things, LOL) I'm back to thinking your right Bob with regard to using the reject water to cut back into the product water for remineralising. Even though in my case the TDS of the reject water is higher than the source water. The TDS of the reject water should consist almost entirely of gh and kh (calcium, magnesium and carbonates) albeit more concentrated than the source water and therefore higher in there respective hardness values. So you will simply need less volume wise to bring the RO water back up to the desired value than you would if using tapwater (by about a quater at a guess). Its still been filtered by both the sediment and carbon filtration so will be 'cleaner' of the minerals that they extract.
I'm also starting to doubt the effectiveness of my carbon/sediment filters and will be changing them a.s.a.p.
Chris.
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Hi all,
I'll ask my more technology minded colleague (who is the technician in the chemistry lab.) when he returns, but I think the differences in the TDS of the reject water maybe to do with the differences in workings, or the order, of the filters.
cheers Darrel
I'll ask my more technology minded colleague (who is the technician in the chemistry lab.) when he returns, but I think the differences in the TDS of the reject water maybe to do with the differences in workings, or the order, of the filters.
cheers Darrel
Roger roger...
Not sure how to do all 4 stages (it's a 3 stage RO, is that why?).. but source, reject and product is no probs (Will do the others if someone tells me how..).. not running DI..
:thumbup:
Not sure how to do all 4 stages (it's a 3 stage RO, is that why?).. but source, reject and product is no probs (Will do the others if someone tells me how..).. not running DI..
:thumbup:
Thanks Mr D
I am stumped I always thought matter was trapped in the membrane and it was the flushing that removed it if the "Nasty s" are suspended in the reject water then what is the point of flushing? & why is my reject water showing a low TDS ? My whole RO world is now upside down.
Regards Bob
I am stumped I always thought matter was trapped in the membrane and it was the flushing that removed it if the "Nasty s" are suspended in the reject water then what is the point of flushing? & why is my reject water showing a low TDS ? My whole RO world is now upside down.
Regards Bob
Hi,
The pipe that goes into your membrane housing from your filter pods is where you need a sample from. The pipe should be connected both ends with just push fit connectors so are easy to disconnect and reconnect by pushing the first ring in towards the connector and pulling the pipe out. Just give it a good push home to reconnect and a tug to make sure.
Chris.
Hi,
Sorry Bob my fault....:whistle:
I think the reason for flushing the membrane is to stop it clogging up.
http://www.purewateroccasional.net/hwautoflush.html
Now about your low TDS. What pre filters are you using and what is the TDS post carbon filtration / pre membrane?
I wouldn't mind betting if I were a gambling man that your carbon filtration is a whole load better than mine.
Also it would be helpful as a comparison if we knew the gh and kh of both the supply water and the reject water as well as all 4 of the TDS readings at the differing stages previously mentioned to get a fuller picture.
I think we'll see a rise in both the hardness levels between the supply and rejected water. A rise in the TDS between the pre membrane stage and the rejected water. But a greater reduction in TDS between your system and mine across the pre filtration stages.
If I'm right that could indicate one of two things.
Firstly my filters are shot and need replacing which I'm going to do anyway as a matter of course and then retest the TDS values. I use the cheapest ones I can find on ebay for my sins which may not be turning out to be such a good investment.
Secondly I think your TDS may be consisting of a different mixture of dissolved solids and those in your supply may be getting dealt with largely by the pre filtration stages in your system. Whereas the solids in my supply, if my pre filters are ok, are of a different chemical make up and go through the pre filter stages.
I'm pretty sure that by the time the water gets to the membrane pretty much all that's left in it is the Gh and Kh components. Which is why I'm starting to look at testing these to try to understand the fuller picture.
Chris.
The firm that sold me the RO unit are going to send me the gubbins to modify it so I can flush the membrane manually..
And once I've done the initial 200 gallons (or thereabouts) I'm going to change the filters..
Got the splitter for the washing machine outlet today (running it off the dishwasher one isn't really practical.. the outlet and waste pipe are tucked behind the fridge, if anything went wrong I'd be a bit stuffed..)..
Just waiting for my water containers and I'm ready to rock'n'roll.. :yes:
L777.. will do that other check once I'm running, no worries
And once I've done the initial 200 gallons (or thereabouts) I'm going to change the filters..
Got the splitter for the washing machine outlet today (running it off the dishwasher one isn't really practical.. the outlet and waste pipe are tucked behind the fridge, if anything went wrong I'd be a bit stuffed..)..
Just waiting for my water containers and I'm ready to rock'n'roll.. :yes:
L777.. will do that other check once I'm running, no worries
Hi Bob,
You haven't read the links I've posted then it makes no difference, that's not what the flush valve is for.
Chris.