Hf4 4021

[ched999uk]

Just doing times on my new hf4 4021 atm. Best so far is. 96secs pure and 15 secs waste. Tap tds is 284. Coming out ro at 017 tds. What's the % on this?

I think the calc is ((Tap TDS - Pure out TDS)/ Tap TDS)*100 So 284-17 = 267, 267/284 = 0.9401, 0.9401*100 = 94.01% TDS is removed.
I would guess you should be able to get that to 98% rejection, so about 6 TDS coming out. It might take a few days to get the TDS down that low with a new membrane.
At 96 sec pure and 15 sec waste that's about 1:6 pure:waste so you might be able to lower the waste a bit.

Hopefully some of the more experienced RO people will answer as I'm not 100% sure on the above but I think it's right.

 

[Iron Giant]

So that's about 2:1 waste to pure which is on the good side of things but I thought that you only had 75tds going in so you could reduce the waste a little. When you close the gate valve you restrict the flow increasing the pressure inside the membrane.

Thanks for this, I have an inline pressure gauge some was setting it up via applied pressure, I can get it to 40psi maybe 43psi but the gate valve is probably 97% closed,

What's shocked is the amount of waste water going down the drain, 1ltr in every 11 seconds that's an insane amount of water wasted

 

[Shinyboy]

I think the calc is ((Tap TDS - Pure out TDS)/ Tap TDS)*100 So 284-17 = 267, 267/284 = 0.9401, 0.9401*100 = 94.01% TDS is removed.
I would guess you should be able to get that to 98% rejection, so about 6 TDS coming out. It might take a few days to get the TDS down that low with a new membrane.
At 96 sec pure and 15 sec waste that's about 1:6 pure:waste so you might be able to lower the waste a bit.

Hopefully some of the more experienced RO people will answer as I'm not 100% sure on the above but I think it's right.

Thanks mate for that. That's given me a headache reading them maths lol. I've got it down now to.. 91 secs pure and 17 secs waste.

 

[ched999uk]

Thanks for this, I have an inline pressure gauge some was setting it up via applied pressure, I can get it to 40psi maybe 43psi but the gate valve is probably 97% closed,

What's shocked is the amount of waste water going down the drain, 1ltr in every 11 seconds that's an insane amount of water wasted

I would say 2:1 waste to pure is high considering your tap TDS is only 75 ( I think). My pressure gauge is between the waste outlet and the gate valve (I have a needle valve). You might find that your gate valve has a hole drilled in it so even when fully closed there will be flow but don't assume it has a hole and close it!
I would probably tweak the waste to get more like 60% waste 40% pure but I would also monitor the TDS out and find the sweet spot as I think resin is more expensive than water if you know what I mean?

 

[ched999uk]

Thanks mate for that. That's given me a headache reading them maths lol. I've got it down now to.. 91 secs pure and 17 secs waste.

The simple maths is the ratio i.e. 91/17 = 5.3 so you have 5.3:1 ratio waste to pure. I would say your waste is higher than it needs to be, I would guess more like 2:1 waste to pure maybe even a little lower say 1.5:1 so 1L of pure takes 1.5 times as long to produce than 1L of waste.

 

[Iron Giant]

I would say 2:1 waste to pure is high considering your tap TDS is only 75 ( I think). My pressure gauge is between the waste outlet and the gate valve (I have a needle valve). You might find that your gate valve has a hole drilled in it so even when fully closed there will be flow but don't assume it has a hole and close it!
I would probably tweak the waste to get more like 60% waste 40% pure but I would also monitor the TDS out and find the sweet spot as I think resin is more expensive than water if you know what I mean?

My gauge is after the pre-filters and before the membrane, it doesn't have a hole drilled as I know Doug ain't a fan of these pre drilled gate valves

Also I don't use resin never a need to

 

[ched999uk]

My gauge is after the pre-filters and before the membrane, it doesn't have a hole drilled as I know Doug ain't a fan of these pre drilled gate valves

Also I don't use resin never a need to

That has just made me think and my gauge is also at the inlet to the RO not outlet.
Pre drilled holes are good for protecting things when people don't understand why the valve is there but they do wear over time with all the pressure of the water going through it.
Your TDS is probably only 2 coming out of the membrane so I can see why you don't use resin.

 

[spruce]

Thanks for this, I have an inline pressure gauge some was setting it up via applied pressure, I can get it to 40psi maybe 43psi but the gate valve is probably 97% closed,

What's shocked is the amount of waste water going down the drain, 1ltr in every 11 seconds that's an insane amount of water wasted

The easiest way to look at the ratio is to put 2 x 20 litre plastic drums next to each other. Feed pure product into one and waste into the other. Then run your r/o. With a tds of 75ppm your waste container should fill only slightly quicker than your pure container.
Then check your r/o pure output with your tds meter. The best waste to pure ratio is when the tds output of the pure before di is at it lowest. The r/o needs to run for around 10 minutes before taking this tds reading.

 

[spruce]

I think the calc is ((Tap TDS - Pure out TDS)/ Tap TDS)*100 So 284-17 = 267, 267/284 = 0.9401, 0.9401*100 = 94.01% TDS is removed.
I would guess you should be able to get that to 98% rejection, so about 6 TDS coming out. It might take a few days to get the TDS down that low with a new membrane.
At 96 sec pure and 15 sec waste that's about 1:6 pure:waste so you might be able to lower the waste a bit.

Hopefully some of the more experienced RO people will answer as I'm not 100% sure on the above but I think it's right.

Exactly the right way @ched999uk to calculate the membrane's rejection rate.

 

[Iron Giant]

The easiest way to look at the ratio is to put 2 x 20 litre plastic drums next to each other. Feed pure product into one and waste into the other. Then run your r/o. With a tds of 75ppm your waste container should fill only slightly quicker than your pure container.
Then check your r/o pure output with your tds meter. The best waste to pure ratio is when the tds output of the pure before di is at it lowest. The r/o needs to run for around 10 minutes before taking this tds reading.

Thanks for this, it's very much appreciated.

I'm really not sure what's the issue with the big difference of waste to pure output ratio,

I do have two 25ltr containers so can do your recommend method of refining the ratio, but I'm thinking I'll need to get my booster pump up and running thus boosting pressure to the membrane and enabling me to tweak the ratio, but I do need some extra fittings and tubing to get the booster pump into operation.

 

[spruce]

Thanks for this, I have an inline pressure gauge some was setting it up via applied pressure, I can get it to 40psi maybe 43psi but the gate valve is probably 97% closed,

What's shocked is the amount of waste water going down the drain, 1ltr in every 11 seconds that's an insane amount of water wasted

It does sound as though you could have a water flow issue as well as low pressure.
When I checked years ago our water flow at the back tap was 13 litres per minute.
When the r/o is working we don't see that much of a mains water pressure drop at the r/o. My r/o uses twice the amount of water yours will.
With my 4040 I found a good start was a little over 2 litres going to waste which produced 2 litters of pure.
I fitted an inline TDs meter. The first inline sensor is on the pure before di and the second is after di.
I now tweek the waste valve to get the lowest TDs output of pure as that will be the best ratio.
You may find that with your old r/o you were using a similar amount of water, just over a much longer period.

 

[Iron Giant]

It does sound as though you could have a water flow issue as well as low pressure.
When I checked years ago our water flow at the back tap was 13 litres per minute.
When the r/o is working we don't see that much of a mains water pressure drop at the r/o. My r/o uses twice the amount of water yours will.
With my 4040 I found a good start was a little over 2 litres going to waste which produced 2 litters of pure.
I fitted an inline TDs meter. The first inline sensor is on the pure before di and the second is after di.
I now tweek the waste valve to get the lowest TDs output of pure as that will be the best ratio.
You may find that with your old r/o you were using a similar amount of water, just over a much longer period.

In the past, I have talked about water pressure issues at our house but I assume it's flow issues so if the waterboard reduces the output during the summer months or work is going on then they reduce the flow no different I guess when running a tap in the house and the washing machine is filling with water that reduces the amount of flow coming out of the kitchen tap,

Yesterday when I was stood looking at the pressure gauge on my 40/21 the pressure didn't drop at all but the pure flow did reduce once or twice as did the waste output my wife may have used a tap in the house or someone in the street could have started with something and affected the flow.

 

[spruce]

If a toilet is flushed or another tap opened, then the r/o is starved of water pressure and flow.

So if the wife is home and wants to water the front and back gardens, then I switch the r/o off for the day. I'll put it on overnight in most cases. I have a float switch so the water to the r/o will switch off when the IBC tank is full.

 

[Iron Giant]

If a toilet is flushed or another tap opened, then the r/o is starved of water pressure and flow.

So if the wife is home and wants to water the front and back gardens, then I switch the r/o off for the day. I'll put it on overnight in most cases. I have a float switch so the water to the r/o will switch off when the IBC tank is full.

Not much chance of my wife watering the garden unless I leave a note, but as I'm now more likely to have to run my R/O through the day she is just a phone call away to check the tank and turn the tap off as required we only have the one tap outside always funny though when she doesn't check if the tap is turned on a and she disconnects the hose from the tap and gets sprayed in the face

I am not overly keen on a float valve in case it fails and my garage which is used solely for storage gets flooded so with a 550ltr storage tank I can't run mine overnight unless production drops right off through the winter, I'll see how things go as I get used to production times

 

[spruce]

Not much chance of my wife watering the garden unless I leave a note, but as I'm now more likely to have to run my R/O through the day she is just a phone call away to check the tank and turn the tap off as required we only have the one tap outside always funny though when she doesn't check if the tap is turned on a and she disconnects the hose from the tap and gets sprayed in the face

I am not overly keen on a float valve in case it fails and my garage which is used solely for storage gets flooded so with a 550ltr storage tank I can't run mine overnight unless production drops right off through the winter, I'll see how things go as I get used to production times

Simply fit an overflow connector on a length of 1/2" garden hose. I ran mine down the side of the garage and under the garage door to the drain where the down pipe is from the garage roof gutters.
A 1/2" garden hose will easily keep up with a forgotten r/o.

 

[Iron Giant]

Simply fit an overflow connector on a length of 1/2" garden hose. I ran mine down the side of the garage and under the garage door to the drain where the down pipe is from the garage roof gutters.
A 1/2" garden hose will easily keep up with a forgotten r/o.

Thanks for this, I have a rectus fitting and some pole hose connected to the side of the tank currently for my old small R/O I'll have to look for some fittings and buy some garden hose, and drill another hole through my garage wall, as I do prefer to run a R/O overnight more so in the winter as then nothing can freeze whilst it's got running water going through it,

It took around 7 hours yesterday to produce roughly 400ltrs but that was through the day so production may have been impacted by my wife being at home, I had it run for 4 hours yesterday morning then had to run it for 3 hours after work and production was a lot faster in the last 3 hours

 

[Shinyboy]

Thanks for this, I have a rectus fitting and some pole hose connected to the side of the tank currently for my old small R/O I'll have to look for some fittings and buy some garden hose, and drill another hole through my garage wall, as I do prefer to run a R/O overnight more so in the winter as then nothing can freeze whilst it's got running water going through it,

It took around 7 hours yesterday to produce roughly 400ltrs but that was through the day so production may have been impacted by my wife being at home, I had it run for 4 hours yesterday morning then had to run it for 3 hours after work and production was a lot faster in the last 3 hours

7 hrs to make 400l is good at 30psi. Well that's better than I'm getting at 50psi.

 

[Iron Giant]

7 hrs to make 400l is good at 30psi. Well that's better than I'm getting at 50psi.

I'll be honest it was a rough guess I may have been out by 50ltrs, I'll have to get myself an inline meter to see what I'm producing as I need to have it sussed out.
If anyone has any recommendations ideally push-fit I did find this Wras Water Meter

 

[ched999uk]

I'll be honest it was a rough guess I may have been out by 50ltrs, I'll have to get myself an inline meter to see what I'm producing as I need to have it sussed out.
If anyone has any recommendations ideally push-fit I did find this Wras Water Meter

Might be worth checking with your water board if you want to claim back the waste charge? Not sure if you can claim for the pure taken away from home as it won't be going down your drain?

 

[Iron Giant]

Might be worth checking with your water board if you want to claim back the waste charge? Not sure if you can claim for the pure taken away from home as it won't be going down your drain?

Just after monitoring pure production and don't want to buy a cheap meter that won't provide an accurate reading

 

[Iron Giant]

So thought this morning as I nedded to run my RO I'd connect my new inline flow meter, 777.7ltrs in around 2hrs so by my calculations I'll need to change my 10" carbon filter every week as they can only process 37,500 litres of pure and waste combined and they are currently £30 each

Edit, as I thought I'd add to this if a add a booster pump to my RO and half production time my thinking is I'll also have the amount of water going through my RO or am I wrong