RO/DI question?

[surgeonfish]

QUESTION: Has anyone noticed a high TDS reading as soon as they turn on their RO/DI units?

I recently noticed my in-line TDS reads 500-1500ppm for a few minutes as soon as my RO/DI turns on! It does gradually drop to 001 ppm after only a couple of minutes. I have the unit connected to an Oceanus Triton top-off controller. Because my RO/DI runs in short bursts, I think my top-off water has been poor. When I actually tested my 55 gal top-off tank with a hand held meter, it had a TDS of 445 ppm. This sucks as the local water yesterday was 145 ppm. I thought I was using good water. This may explain my recent algae problem.

Has anyone else noticed such high initial TDS readings from their systems? Does anyone flush or discard their initial water before collecting it?

System:
Maxxima Hi-S RO/DI Filter. I recently added a second Hi-S RO unit (120 GPD). All my filters are less than 6 months old. I flush the unit weekly.