New Member and TDS Measure?

[jtreath]

Hi all;

New to the forum so a big Hello to all!

My question is in measuring water quality of RO water. I have been doing water changes and top offs with some RO water I purchsed from a store. I have been fighting algae and cyano blooms for 3 weeks now. My params are:

Ammonia 0
Nitrites 0
Nitrates <5
pH 8.2
Temp 78
SG 1.0255
Ca 450
Alk 110
Cu 0
Fe 0
PO4 0

All of these values have been steady for 3 weeks (Daily testing). I did have an ammonia spike 5 weeks ago that settled down after 4 days. This is a new to me set-up that I purchased 6 weeks ago. The spike happened after the move and the LS and LR had been disturbed.

With my Nitrates and Phosphates both being 0 I decided to get a Hannah TDS metre to check my RO water. It registers at 23. Is this an indication that he RO water is not good quality? Should my TDS reading be 0? What is a good reading? BTW my city water supply measures at 30.. so I can only assume that the RO water is not good. Would this be why I am still fighting a losing battle vs. algae and cyano?