Base rock raising TDS?

[AMDPhenomX4]

Ok well, I was filling my 180G and checked the in tank water TDS and it was over 600. I put the meter below the sand and got a lower reading. Could the rock be raising my TDS? My rodi is at 0TDS. Their is no salt in the water.

 

[thincat]

It's more then likely the die off on the Baserock. I would not worry about it as it will be removed or decompose with the advant of good bacteria and water changes.

 

[AMDPhenomX4]

Ok thank you.

 

[Kurt_Nelson]

That's interesting that the crud from the rock will raise the TDS that much, but I suppose it's not hard to imagine. I would imagine that the sand bed is acting as a filter and keeping much of the "total dissolved solids" from finding the meter. But as long as your incoming water is at 0ppm TDS, I wouldn't worry about it.