Does anyone else make their own Vitamin C serum?🤷‍♂️🍊

I was sick and tired of my vitamin C serum’s oxidizing after only a couple weeks of opening them. I spent all this money on an expensive vitamin C serum and only got to use about an eighth of it (even if I stored it in the fridge!!!!). I saw a post on FB about how someone made their own vitamin c serum and loved it. After a little research, I ended up buying 100% L-Ascorbic Acid powder, 3% resveratrol + 3% ferulic acid serum, Snail Mucin essence, and a topical vitamin e oil. I make a vitamin c serum every morning in the palm of my hand. It literally takes less than 60 seconds. In the beginning, I made sure the pH of my serum was between 2.6-3.5 with pH test strips. It took a few days with trial and error to concoct a vitamin C serum that works perfectly with my skin. Now I know exactly how much of each product I need to make a 20% Vitamim C serum with a stable pH of 2.6-3.5. The vitamin E oil and ferulic acid help stabilize the Ascorbic Acid and they work better with it. I’m never going back to buying a premade vitamin c serum ever again. I’ve been using my homemade vitamin C serum for the last 2.5 months and I can see a HUGE difference in my skin compared to the premade vitamin c serums I would buy (Mad Hippie Vitamin C serum, TO Vitamin C suspension 23%, Timeless Vitamin C+E Ferulic Serum, etc) Also, it’s pretty cheap, especially for how long these will last. After 2.5 months I’ve barely made a dent in the Ascorbic Acid powder. it doesn’t oxidize much at all because it’s in powder form. It suspect it will last me over 1.5 years!!! 😲 Prices: 1) TO L-Ascorbic Acid Powder: $6 2) TO 3% Resveratrol + 3% ferulic acid: $8 3) Cosrx Snail Mucin essence: $16 4) Finest Nutrition topical Vitamin e oil: $6 Total: $36 Have any of you tried making your own Vitamin C serum? If so, what products did you mix with the powder? I’m running low on my Snail Mucin and I’m looking to buy it again or even something new.