TDS meter readings?

[Kenzor]

Just wondering is what the absolute maximum TDS reading you should allow is? I live in a very hard water area (around 450 reading) with slow running tap water. I have to use a pump to get PSI to the desired amount, otherwise my tank will take forever to fill up. The problem is, with the pump on, I think I’m almost filtering water too fast as the TDS reading creeps up to 5+ and I’m not sure when I’ll start to get spotting?

 

[The Cleaning Warehouse]

Hi Kenzor, 450TDS IS very hard!!! This is a question that we have asked our window cleaning customers alot and to be honest most of them allow a threadhold of upto 10TDS.....however with every TDS above 000 you are increasing the probability of spotting and therefore an unhappy customer. I would always try and keep it as low as possible (preferably 000) however if you should be ok if you occasionally use 5TDS.

 

[Kenzor]

Hi Kenzor, 450TDS IS very hard!!! This is a question that we have asked our window cleaning customers alot and to be honest most of them allow a threadhold of upto 10TDS.....however with every TDS above 000 you are increasing the probability of spotting and therefore an unhappy customer. I would always try and keep it as low as possible (preferably 000) however if you should be ok if you occasionally use 5TDS.

Thanks for your reply! How often would you recommend changing filters with a TDS as high as 450? I think mine may need a change very soon.

 

[The Cleaning Warehouse]

Hard to say really, Im assuming we are talking about the pre-filters.....How many litres do you purify per day? How big are your prefilters 10" or 20"? As for the resin you need to change this as soon as your reading increases.

 

[Deleted member 7446]

@Kenzor have you considered rain water harvesting or do you have the space for a rain water collection tank or IBC 

Im in North Devon and my household cold water supply is straight from the main at 58 ppm and my rainwater storage is between 40 & 50 ppm 

I really feel for all you guys up North with hard water 

 

[Part Timer]

I really feel for all you guys up North with hard water

The OP is from Somerset, while I appreciate that is north of you but south for the vast majority ?

 

[The Cleaning Warehouse]

The majority of England is south for you Part Timer ??

 

[ks789]

Just wondering is what the absolute maximum TDS reading you should allow is? I live in a very hard water area (around 450 reading) with slow running tap water. I have to use a pump to get PSI to the desired amount, otherwise my tank will take forever to fill up. The problem is, with the pump on, I think I’m almost filtering water too fast as the TDS reading creeps up to 5+ and I’m not sure when I’ll start to get spotting?

Mines at 4 lately, but not changing the resin yet, as when its sat in the container a while it dips down to 3, 2, sometimes 0. Mines 530 out the tap ( east suffolk, Ipswich/woodbridge area) but ro gets it to 13, then di it. Change first pre filter (sediment) approx every 10/12 000 litres (inc waste) and carbon filter 35000 litres. thats for a 40/21.

 

[J and S]

Hard water up North?

Think most if not all of Scotland is soft as is Merseyside, Manchester, Lancashire, S and W Yorks, N Wales........most of the hardwater is in the South and S East.

 

[dazmond]

Just wondering is what the absolute maximum TDS reading you should allow is? I live in a very hard water area (around 450 reading) with slow running tap water. I have to use a pump to get PSI to the desired amount, otherwise my tank will take forever to fill up. The problem is, with the pump on, I think I’m almost filtering water too fast as the TDS reading creeps up to 5+ and I’m not sure when I’ll start to get spotting?

im DI only as my tap water is only 028 but its currently coming out of my resin vessel at 005,ill go up to 010 before i change the resin,never had a problem with spotting at these low readings?......

 

[Pjj]

We always run at a tds of 000 resin is changed as soon as we get a reading . I guess Ime lucky as we use twin ros and our tap tds is around 90 

 

[Iron Giant]

@Kenzor I would say the lack of information provided isn't helping, do you have a standard cheaper R/O  a 40/40 or 40/21 I am guessing that you have a standard R/O as pictured below, without detailed information we are simply guessing 

 

[Kenzor]

@Iron Giant That’s a fair point, I’m fairly new to the game but I’ll upload pics of my setup in a bit.

 

[The Cleaning Warehouse]

If your TDS from the tap is 530 and your RO is bringing it down to 13 then this is a 97-98% purification rate and is very very good. Alot of our customers only see a return of approx 90-95% and therefore their TDS after the RO is higher then yours even with a lower starting TDS. Most of this reason is down to their water pressure being low but still think yourself lucky to get the results you are achieving with such an incredibly hard water supply. 

Just keep the water that you clean with as close to 000TDS and you'll be fine. ?

Change your Pre-filters periodically, although this doesn't have a direct affect on the TDS reading what it will do is protect and prolong the life of your membrane so you wont have to replace it so often.  

Keep checking the water coming from the RO (but before the DI) at the moment you say its around 13TDS......over time this will increase as the membrane gets older. You need to make a decision to at what point it becomes economical to pay the cost of new membranes VS the extra cost in Resin that you will be using to bring the higher TDS down to 000.

Good luck with your business!

 

[Kenzor]

In the meantime I use this:

Pentair Water RO system

 

[spruce]

@Iron Giant That’s a fair point, I’m fairly new to the game but I’ll upload pics of my setup in a bit.

An r/o is a fairly simple piece of equipment to manage when you understand it.

The first 2 housings are your prefilter housings containing first a sediment filter and then a carbon filter.

These 2 prefilters protect the membranes. The sediment filter removes sediment and the carbon filter removes chlorine. Chlorine destroys membrane material.

They need to be changed regularily. (We have 20" prefilters and the carbon filter is a Fiberdyne which is good for removing chlorine from 76,000 liters of water, both waste and pure added together. We change them every 3 to 4 months when the meter tells us 76k is up.)

Membranes are changed when they start to deteriorate/ become less efficient. The advice of a supplier once was to consider changing membranes when they are removing less than 94% of the dissolved solids in the water. Using your water tds as an example, membranes would need to be changed when the tds of the pure water from the membranes is 27ppm. (You might even decide to change membranes before that when you factor in the increasing cost of resin when compared to the cost of replacement membrane/s. My membrane doesn't work as hard as yours and the will be 7 years old in September. My 4040 membrane is still removing 97% of the minerals in our water. However, your water is harder and your membranes can't be expected to last as long as ours.

The final stage is the di vessel which polishes off or removes those remaining dissolved solids that are too small for the membrane to filter out.

We focus on 0ppm leaving the di vessel into our storage tank, but will tollerate 1 until the prefilters need changing and do everything together. I won't let it go above 1ppm. Some cleaners tell us that its fine at 10ppm or every higher, but in low sun I can see minute spots on our windows looking out at anything above 4 to 5ppm. I doubt a customer would notice them but I'm not going to take the chance.

 

[spruce]

In the meantime I use this:

Pentair Water RO system

View attachment 16922

Unfortunately it isn't the most efficient r/o available. It wasn't built for window cleaning applications. It was built for American kitchens as a third tap in the sink for pure drinking water.

My mate down the road had the previous model Merlin and he never got any better results than removing 90% of the water's tds. The newer ones are slightly better but not much. They don't send as much water to waste as the earlier ones did though.

 

[dazmond]

finally changed my resin today.......a 25kg bag of mb115 has lasted me 5 months(last changed on 25th jan).thats the longest a bag has lasted me,its usually 3-4 months,my tap tds has gone as low as 024 though some weeks and maybe im doing less work or being more efficient with my water,i dunno.......

 

[Jesse234]

Hi Kenzor, 450TDS IS very hard!!! This is a question that we have asked our window cleaning customers alot and to be honest most of them allow a threadhold of upto 10TDS.....however with every TDS above 000 you are increasing the probability of spotting and therefore an unhappy customer. I would always try and keep it as low as possible (preferably 000) however if you should be ok if you occasionally use 5TDS.

Hi I’ve just had my osmo compact tank fitted today at pure freedom, they gave me a tds meter he checked it when there but he only had small amount of water in the tank and it was coming out not at 000 , he said it’s probably because it’s the first lot in the tank so for me to empty it tommorow and fill and check again. I live in a soft water area , so when testing the water do I want the reading to say 000, as I just checked it there and it says 031

 

[ched999uk]

Hi I’ve just had my osmo compact tank fitted today at pure freedom, they gave me a tds meter he checked it when there but he only had small amount of water in the tank and it was coming out not at 000 , he said it’s probably because it’s the first lot in the tank so for me to empty it tommorow and fill and check again. I live in a soft water area , so when testing the water do I want the reading to say 000, as I just checked it there and it says 031

Yes 000.

 

[Iron Giant]

If you have an RO fitted to your tank it will need flushing, if you have had a DI fitted then just check the water going in from your hose from your tap is on the correct side as there are arrows on the head of the vessel to indicate which side is water in and out also check it's actually been filled with resin