Water Expert Needed......

[buce_n_gar]

Hi, I'm looking for suggestions for the water in my 10gal aquarium. Here are my readings:

NITRATE - 20ppm (safe)
NITRITE - 0ppm (safe)
HARDNESS (GH) - 150ppm (hard)
ALKALINITY (KH) - 20ppm (low)
(PH) - 8.2 (alkaline)

I have one Betta, five feeder guppies (small), five ghost shrimp, and a few Malaysian Trumpet snails in the sand substrate. I aerate using a small stone and have a mechanical in-aquarium filter. All the fish and inverts seem fine. My concern is twofold: first that the KH is so low, and second that the PH is so high. I understand that typically stability is more important than readings but the PH reading is consistently high. How can I reduce it?

I have read you can increase the KH by adding a small amount of baking soda and I have considered it, but I have also read that a low KH can eventually lead to a PH drop. Is this correct?

What are your suggestions on how to handle this?

[sergo]

low kh can cause some swings in ph. yes you can add some baking soda. how much? i don't know. you just add a little bit, test, add/test until you get it where it needs to be. you can lower ph using an acid buffer but most will say don't jack with it. i did it to my tank over the course of a month or so (7.8 to 7.0). i did it very slowly so i can see how the buffers act in the tank. i also use r/o water that is unbuffered over plain tap water so i kind of have to use them a little. basically you have a chemistry lesson on your tank with fish in it so be careful. it's up to you what you actually do but whatever you do make sure you understand what's going on or you'll end up in disaster. read, read, read and then ask questions.

[Chrona]

I think the hardness is also buffering the water. Not sure how it works exactly, but calcium works together with carbonates to buffer. The aerator will raise pH a bit as it drives the 3-4 ppm of CO2 out of the water, but not by that much. Normal pH with 20ppm kH is about 7.1-7.2.

Adding 1/4 teaspoon of baking soda will increase the kH of a 10g tank by about 20 ppm, but I wouldn't mess with it. Livebearers, snails do great in hard/akaline water and the betta will adapt. Everything looks fine to me.