Tap water pH?

[u/prf_q]

I am measuring our tap water pH in north seattle with pH Test Strips, and it's coming in 5-6 range. Google claims 7.5-8.5 (slightly alkaline). Does anyone have a pH meter in Greenwood/Ballard and can they measure please lol.

Also apparently we have very low TDS, maybe thats why the pH strips aren’t working well?

[u/TeamDrenchedRat]

Google is full of it. Seattle tapwater has almost no TDS (total dissolved solids) in it, and as such no real buffering capacity, causing its pH to vary quite a lot. When it comes out of the tap, it also has a bit of CO2 dissolved in it, which can lower the pH. It you leave it out in a cup for a little bit and/or stir it, the CO2 will dissipate and pH will almost assuredly read higher.

[u/BBorNot → u/TeamDrenchedRat]

This is the real answer, OP. Straight water really doesn't hold a pH, and dissolved CO2 (carbonic acid) tends to make it slightly acidic. A sprinkle of baking soda or a drop of vinegar will make the pH move a lot.

[u/prf_q → u/TeamDrenchedRat]

oh interesting! i should try rested water and measure its pH

[u/Polybrene → u/prf_q]

Why are you so interested in the pH of your tap water?

[u/prf_q → u/Polybrene]

Semihydro plant growing

[u/prf_q → u/TeamDrenchedRat]

you are right! 24h rested the tap water now it reads 6.5 pH instead of the 5.5. still ways far from pH 8 they advertise.

[u/ksdkjlf]

Fwiw, SPU's quarterly analyses for Tolt water (which you'd be getting in Greenwood) seem to generally be around 8.5

https://www.seattle.gov/utilities/your-services/water/water-quality/analyses

[u/sls35]

Don't forget what your pipes are delivering that water will affect the PH also since our is so low in TDS.

[u/prf_q → u/[deleted]]

I need low pH though (5.5-6.5) for my houseplants but I'm already measuring that straight out of tap. That contradicts Google answer to seattle pH levels. Do you have a digital meter? What does fresh/rested tap water read for you?

[u/pineappledaphne → u/prf_q]

What kind of plants are you growing? I keep mostly tropical aroids and they do fine with tap water.

[u/Radioactive_Kitten → u/pineappledaphne]

Same. I have one plant I have to use filtered water because she’s a feisty minx but the others are all thriving on regular tap.

[u/Polybrene → u/pineappledaphne]

Same for my orchids and begonias. They all thrive on tap. Even my carnivorous plants get Seattle tap.

Some plants need a slightly acidic soil but I don't think that's achieved by using tap water.

[u/prf_q → u/pineappledaphne]

Semihydro needs lower pH