RO water parameters

[BREWERS DROOP]

So i use a 5 stage RO water filter, it takes 2 days to get my water, as its not got a pump, question is, the water TDS meter comes out at 0 as it should, the water in is 256.
Whe i want to fill my kettle without the resin filter, (the final stage) the TDS is 25, and it takes only 20 mins to get my water.
What effect of a reading of 25,can this have on mineral content? and additions, probably near on impossible to distinguish which ones, without analysis.
Any thoughts

 

[Rob11TC]

Mine goes in at 260ish and out the membrane 4 or 5! I have a booster pump though and double membrane!! 0 tds after DI resin for my fish tank. It takes about 40 to 50 mins to get my water for brewing about 35mins for my 25l RODI for my fish.
I'm sure the only way to tell what's left is to get an ICP test (think that's its called) on your RO water. Most marine shops or online.

 

[strange-steve]

I would say 20ppm tds means all the important values (calcium, chloride, sulphate, alkalinity) are as close to zero as makes no difference.

 

[BREWERS DROOP]

I am thinking of removing the resin filter altogether, as i need to brew as and when, and thinking the parameters as you state are low, it wont make any odds