that means your water is only moderately hard. The pH drops because teh co2 gasses off. The initial readings are falsely high. You can do wc's with your tap immediately, it won't cause a problem. The aeration in your tanks willl take care of it.
Okay - so I just need to keep the water changes small? Seems like when I do a change of more than about 25% they get all funky - close up tight and stay on the bottom for a day or 2. :huh:
