a good portable RO unit?

[hbeth82]

Thanks everybody for all your help (and the distraction from work)! One question I'm still stuck with - how important is it to have a TDS meter? I understand that it measures the total dissolved solids in a solution and thus tells me how much other stuff will be in the water in addition to the H2O, though it doesn't tell me what that other stuff is, only that it's there. However, is it sufficient to have the API test kits for ammonia, nitrite, nitrate, GH, & KH?
Thanks!

 

[cmor1701d]

A TDS meter will tell you when you need to change your DI cartridge (TDS >0). I change my DI media when my TDS =>3.

The WHO report that was linked states "

The possible health consequences of low mineral content water consumption are discussed in the following categories:"

As Jonathan stated earlier, I don't think anyone is suggesting that you drink RODI water as your only source of liquid. Have a cup of tea or a glass of milk too <g>.​

 

[hbeth82]

A TDS meter will tell you when you need to change your DI cartridge (TDS >0). I change my DI media when my TDS =>3.

Thanks. So it's not something that I'll need up front in order to decide how much of the Kent RO / Seachem Equalibrium I'll need to add, that can be done with the GH test kit? Once a month or so, use the TDS to make sure the DI part of the unit is still doing it's job? Plan on getting one, just trying to prioritize everything that I'll need to get and when I'll need it, so if I can hold of on the meter for a few weeks, that helps.

How much waste water does your RO/DI generate? According to the seller, the unit Kungpaoshizi got generates about twice as much waste water as it does clean water, 8.4gal & 4.2gal, though for the 150gpd unit, the amounts of clean and waste water generated are about equal.

 

[Kungpaoshizi]

The TDS meter will just show you how well your filters/unit are doing.
So you have an idea of what it is out of tap, also to be certain you have 0 when making a batch of ro/di...
Otherwise when you test the output and you see it start to rise, you know your filters are about to the end of their life.

 

[cmor1701d]

RODI units have about 4:1 waste:RODI water ratio.

TDS of the tap really doesn't mean all that much for public water. For well water it will give a general idea of what your dealing with. Public water supplies will vary from a hour to hour. Mine is between ~180 - ~230. I've heard both better and worse numbers from folks around the country.

My RO tds is generally below 2-3 (98% rejection rate 0f ~200 tds tap) and it's 0 after the DI. Because my tap water is only around 40psi and gets quite cold in the winter I bought a booster pump and pump the pressure to ~70 psi which is the sweet spot for the RO membrane. Water below 50psi a/o 50 degrees has a pretty drastic reduction of water output.

 

[hbeth82]

Any ideas, on average, what your nitrate and hardness levels are after just the reverse osmosis? I know this depends largely on what they were before the RO but just curious.

If I use only the RO, are the conditioners (Equalibrium or Kent RO, or whatever else) still necessary?

 

[Kungpaoshizi]

It will largely depend upon your test results...