Lowest TDS to breed..

[utiliy]

I usually keep it about 60 to 70...bit what's the lowest a guy could go...as in the softest..
0?

[LizStreithorst]

You can breed in 0 TDS. I've done it. If you want for sure 0 TDS water use distilled. RO still has trace amounts of TDS too low to be read on the meter.

[jeep]

Be careful, lowering the TDS too far can cause a ph crash. 60-70 should be fine.