Cycling 5 Gallon - PH drops?

[CrowGoat]

Howdy.

First post here and back to an aquarium after 20 year layoff. I'm cycling (fishless) a small five gallon with live plants. Everything has been going along fine, and the cycling has just started (see readings below), but I noticed that as the Nitri(a)tes have started to rise, the PH is taking a drop pretty quick!

I plan on a small school of Endler's and perhaps a few shrimp later. But this drop in PH has me wondering....

Last week, the PH had been holding steady at about 7.1 Today's readings are:

Ammonia: .25
Nitrite: 2ppm
Nitrate: 10ppm

PH: 6.6

So I take it the cycle is ramping up. But:

Why the sudden PH drop?

Secondary: should I start water changes or is that not necessary since it's fishless?

Thanks.

 

[Fresh2o]

Welcome to AA and welcome back to the hobby.
The pH drop may be a natural occurrence as a result of nitrification (by the bacteria). It may be further enhanced by a low KH level. I would not worry about it unless it drops below 6.0