Ro Waste Water

[scrim it]

Do you keep the waste water valve on half way while filling the ibc tank or how much should this be turned on while purifying water?

 

[scrim it]

I'll try again and word my question better. New to this and not sure I'm doing it right.Currently my tap water is 042.

I purify it through the sediment and carbon filters, the 4040 RO (WASTE WATER TURNED FULLY OFF) and finally the di. From the di I run a hose straight into the van 350litre tank. It takes 1.5 hour approx to fill.

I know I don't need a RO as my tap water is low but I got it with a lot of other equipment 2nd hand so took it anyway with the thought that the di will last longer.

My question is do I need to have the waste water valve turned on when I'm filling my tank and if so, how much should it be turned.

I tried it today and had the waste water valve turned on by a quarter. The ppm coming out of the waste water was 068. How can this be if the tap water is 043.

 

[Duncs]

i flush my RO for 15 mins prior to purifying my water by opening the waste water tap fully

after 15mins i purify my water by fully closing the waste water tap

the guys will be a long later to explain better

if your readings are so low you could fill your tank from TAP then thro your DI

thats what i would do RO takes ages

 

[scrim it]

Thanks for the reply. The RO only takes 1.5hours to fill my 350lt tank. That's not too long as I can do it at night. So you never purify your water with the wate valve open a little? Do you fill your tank straight from the RO or do you fill a IBC tank first.

It's just I hear people always saying about how much waste water an RO uses but I don't understand what they mean?

 

[Duncs]

when i purify the water the waste water is closed

the waste water still comes out the pipe tho

i purify to my van this is ok if you are only using 350l

but i have garden buts in garage 1000l tank would be better tho

the waste water tap is only ever open when flushing prior to purifying

 

[scrim it]

I will flush the ro before purifying from now on. There is no water commingled out out the room while I'm purifying. Should it be?

 

[Chimera]

If your RO system has a pre-set waste output and the saddle valve is used purely for flushing, see below. If not see Dougs post below.

If purifying down from a high PPM (350+ I believe) there is some merit to leaving the waste valve slightly open (Less than a quarter turn) to ease the workload of the membranes making them last longer at the expense of of slightly more waste water.

Regardless of input PPM it's worth flushing for 10 or so minutes before each use to prolong the life of the membranes.

If purifying down from rain water you can recycle your waste back into your rain water storage butt until it's ppm reaches 75 at which point it must be emptied to start again (I've yet to have to do this mind).

 

[scrim it]

Thanks chimera. I will flush then keep valve closed.

 

[gto]

no you need the waste valve open. at least 50/50 (depends on your RO)

when you purify the waste is building up on the outside of the membraines, the waste water washes the waste particles off.

with the waste tap closed you are forcing everything through the membraine, so the waste particles will block up the pours in the filter killing it.

your RO wont last very long.

with low TDS go with DI only or pay a lot to change membrains every couple of months.

 

[jimmyboots]

I do the same as Duncs. Open the waste when you start and take a reading of the water before it runs through the DI. by disconnecting the pipe. The reading will be high as it flushes any waste particles through.

After 10 minutes or so the reading will drop as the filters run to their maximum efficiency.

I then close the waste valve (waste water still comes out only less, as Duncs said) and connect the pipe back up to the DI and let the pure run through.

This makes your Resin last longer as it never has to work hard reducing the TDS for the first 10 mins or so.

My reading from the tap is 250. If it was 43 I would probably use just a DI. Either way with 043 tap water, if you flush your membranes for 10 mins prior to filling, your membranes, filters and DI will last forever /emoticons/biggrin.png

 

[gto]

it sounds like your RO has a pre set waste output. (should be 50% Min)

i was reading it as there was no waste out put at all as you turned it off

 

[doug atkinson]

To prolong the life of your membrane it needs to be set as 60 waste 40 pure however you can do 50/50 but this will effect your ppm out.

Shutting the valve off on the waste will damage your membranes, they will clog up in no time. NEVER DO THIS as you will blow the membrane sheeting.

 

[Chimera]

Have amended my previous post to reflect the need to ensure that the RO system needs to have a pre-set waste output as I thought this was standard.

 

[scrim it]

Thanks everyone. I have been doing it wrong up until now. I have been purifying with the valve completely closed and no water coming out. I've flushed occasionally between fills. I've been doing this for a few weeks. I will start to purify with the waste valve 50% open from now on and hope I've not wrecked my RO. Any way I could check if I have?

 

[Duncs]

hi guys just been reading the threads so the crack is outlet waste fully open to flush system 15mins prior to purifying then

dont fully close tap say 50/50 open using pump also

4040 purefreedom

at the moment only got 4 weeks out of my resin

whats your thoughts guys sure purefreedom said close tap when purifying

 

[Duncs]

when i was purifying with the waste outlet closed still got more water waste than pure

 

[Andy1979]

Hi I'm new to all of this and I am trying to find out how much waste water I will approx have on a 350lt tank

Any help would be greatly appreciated

Thanks Mark

 

[spruce]

Adjust the waste valve so you are getting a pure to waste ratio of 50/50. So you should fill 2 litres of pure to 2 liters of waste.

This works best for us with a tap water tds of 120ppm.

If you had a high tap tds, then you would probably need to increase the waste to pure ratio ie. 60 or 70% waste to 40 or 30% pure.

However, if you are on a water meter then you will need to find the balance between the cost of early membrane replacement and water costs.

 

[Andy1979]

Thanks ever so much mate, I don't think that's going to be any good for me as I live in a terraced house that has a communal car parking and the van would be parked about 80ft away from my house with nowhere to run the waste water too. We live in a medium water area and looks like I'm going to have to go the DI route do you know roughly how long a bag of resin would last as trying to work out sort of cost per house.

Sorry for long message

 

[spruce]

Hi I'm new to all of this and I am trying to find out how much waste water I will approx have on a 350lt tankAny help would be greatly appreciated

Thanks Mark

Depends on your r/o.

The RoMan type r/o we got originally had an inline restrictor on the waste which was 3 waste to 1 pure. So if you had one of these then you would use 1400 liters of water to produce your 350 liters of pure. ( 350 + 1050 = 1400 liters.)

A one time RoMan used to sell an inline restrictor which was a 5 waste to 1 pure.

The 4040 we have now has a gate valve on the waste which has a 1mm hole drilled through the 'gate' so its impossible to turn the waste off completely. After flushing I slowly close the gate valve until I get the best pure reading and then open it fractionally. I got the inline tds meter from Doug a few years ago.

At a 50 50 waste to pure ratio on my 4040 r/o I would use 700 liters to produce 350 liters of pure.

 

[Andy1979]

Thank you mate I think I'm going to have to go the DI route and use the resin instead