How do I increase my pH??

Hi guys! I'm very new to the hobby and I was wondering if someone could help me figure out my pH situation.
My ammonia and nitrite levels have been 0 for about 1 1/2 months now, and my two platies have been doing really well ever since I got them a few weeks ago. I check my water parameters religiously every morning using my 6 in 1 test strips from SJ wave as well as my ammonia test kit from API. The only thing I noticed that makes me a bit nervous is my water is extremely soft.. like its basically 0 unless I use a bunch of equilibrium when I do my water changes (I do 2 tbsp each water change). Even then, my water level is still below 100 ppm. Additionally, my pH is very low too as its at a stable 6.4. When I went to my lfs, the woman working there told me to add baking soda.. but I'm scared to do that because I don't want to shock my fish. I would like to get my pH around 7 at some point (as I want to add a betta and one more platy), I just dont know how to go about it. I purchased crushed coral but I havent added it yet because I have no idea how it all works. How much do I add to a 20 gallon tank, or should I not even add it? I added a piece of coral/stone to the tank but it didn't change my gH or pH. I also bought API's proper pH 7.0 but again.. I'm too scared to add it because I dont want hurt my fish! What can I do to increase my gH and my pH effectively.. without risking the health of my fish?

Thank you so much for any help you can offer and I apologize for sounding like such a newbie!

Water info:
20 gallon tank
Temp: 76
Ammonia: 0
GH: 0-100 ppm (probably 0-10 ppm)
NO3: 0
NO2: 0
Cl2: 0
KH: about 120 ppm (maybe a bit lower)
pH: 6.4

 

that's fine, i don't see why you need to increase it. as long as it's constant

 

The great thing about crushed coral is you aren't going to add to much. It is only going to raise your pH to a certain level and no more. I can't tell you what that number is going to be because it depends on the chemistry of your water. The number I get won't be the same as what you will get.

If you have coral chunks add about a cup full to a media bag, if you have the CC ground to almost a sand put 1/2 cup in a very fine media bag, with either rinse it off and put it in your filter. If it isn't rinsed first it will raise the pH too quickly. As it very very slowly dissolves it will gradually raise your pH up.

I add very few things to my tanks but I do run crushed coral and add Equilibrium to compensate for my very soft water with very little mineral content.

 

The great thing about crushed coral is you aren't going to add to much. It is only going to raise your pH to a certain level and no more. I can't tell you what that number is going to be because it depends on the chemistry of your water. The number I get won't be the same as what you will get.

If you have coral chunks add about a cup full to a media bag, if you have the CC ground to almost a sand put 1/2 cup in a very fine media bag, with either rinse it off and put it in your filter. If it isn't rinsed first it will raise the pH too quickly. As it very very slowly dissolves it will gradually raise your pH up.

I add very few things to my tanks but I do run crushed coral and add Equilibrium to compensate for my very soft water with very little mineral content.

Thank you for your advice, I'm going to add some coral then. I was wondering if I could also just add the crushed coral into my tank directly or would it be better to add it to the filter via a media bag? Again, thank you so much!

that's fine, i don't see why you need to increase it. as long as it's constant

Thank you for your reply! I do agree that a steady pH is probably better, I just wanted to make sure I wasn't putting my fish at risk. Thanks!

 

Thank you for your advice, I'm going to add some coral then. I was wondering if I could also just add the crushed coral into my tank directly or would it be better to add it to the filter via a media bag? Again, thank you so much!

Thank you for your reply! I do agree that a steady pH is probably better, I just wanted to make sure I wasn't putting my fish at risk. Thanks!

I feel it works better if it can be put in the filter or at least where it has the most water running over it. Right below the output of a HOB should work almost as well as in the filter. That way water is running over it and that water is being pulled back through the filter and dispersed throughout the tank.