What is going on with my water?

[Johnny B. Goode]

My water comes out of the tap at 7.2. The only thing I add to it before it goes in my tank is dechlorinator. Just regular bagged gravel from Lowe's as the substrate. I rinsed that extremely well before it went in the tank though. Why then in the tank is my water showing 8.8? This is a 10 gallon tank that has been set up for about 4 weeks now. There are some moss balls, a couple dwarf chain swords, 2 java ferns, and 2 dwarf Lilly bulbs. No fish. I do use seachem flourish in the recommended dosage once a week. Im not convinced the tank is cycled though. Ammonia 0 nitrite 0 nitrate 5. I want to eventually add cherry shrimp but at a ph of 8.8 plus I don't think I'll be able to do that.

EDIT: I also use aquarium co op root tabs.

Edited December 25, 2020 by Johnny B. Goode

[Jack.of.all.aquariums]

You might try letting your tap water sit in a bucket with an airstone for a day before testing it's pH. Sometimes your water utility will artificially lower the pH of the water to protect plumbing. One of the methods they use is co2. As it sits the co2 off gasses and the pH climbs. 

[McNubbin]

I agree with Jack. Pull some water from your source, let it sit over night then test it. Gasses in the water can give false readings. My water goes from. 6.8 out of the tap to 8.2 after degassing.

Also, those home depot stones may in fact be adding hardness as well. Easy way to tell is to pour some vinegar into a cup, dump in some stones and see if they start bubbling. It won't fizz up like baking soda or anything, but you will see small streams of bubbles rising up from the rocks. If they bubble, they are adding hardness and raising the Ph.

[Johnny B. Goode]

2 hours ago, McNubbin said:

I agree with Jack. Pull some water from your source, let it sit over night then test it. Gasses in the water can give false readings. My water goes from. 6.8 out of the tap to 8.2 after degassing.

Also, those home depot stones may in fact be adding hardness as well. Easy way to tell is to pour some vinegar into a cup, dump in some stones and see if they start bubbling. It won't fizz up like baking soda or anything, but you will see small streams of bubbles rising up from the rocks. If they bubble, they are adding hardness and raising the Ph.

Thanks for the advice. I've got water in a bucket bubbling with an air stone right now. I'm going to test it tomorrow. I tried the vinegar trick and got no bubbles. Thanks for telling me about that. I tested the water before I started bubbling it and got 7.2. Do you think seachem neutral regulator would be a good option for keeping the ph neutral or close to it?

[Johnny B. Goode]

Just wanted to tell both of you who replied thank you. The CO2 from the water department must be what is going on. The water hasn't set for 24 hours in the bucket yet and it has already made its way from 7.2 to 8.4. I imagine it will make it to 8.8 after the full 24 hours. I've got some neutral regulator on the way. I was hoping to run this tank without any additive other than dechlorinator and ferts but I really want cherry shrimp in it and I don't think they will do well at 8.8. Anyway thanks again for the advice.

[McNubbin]

@Johnny B. Goode if you are looking to keep shrimp,  there are variants that thrive in hard water. If that's not something you want though it might be worth while to consider rainwater collection (if legal where you live) or reverse osmosis. Personally I think I might rather add in the GH and KH I need than add another chemical altogether to bring it down.

Edited December 26, 2020 by McNubbin