So, I have a buckeye RO/DI setup HERE

I changed out all the filters before I stared adding water to my in wall build. The meter read zero. I have made 275g with it and started to fill my big tank. Right now the tank reads ~300 TDS!

Tap water here is 450-500 TDS.

Can it be possible that the filters only last a few hundred gallons?

Can I use the water with 300 TDS?