Low soil ph

So I was starting to see deficiencies on one of my plants. I ran some water around 6ph through it and metered what came out. It was 5.2 coming out the bottom of the pot. So I ran a few liters for 7ph water through with no improvement. I read online that dolomite lime seems to be the best solution. Was looking for your guys opinions. To use the lime do I just have to top dress it and water? My plant is in fox farms ocean in a 1 gallon pot.

Repot them into a 3gal or 5gal....you may be root bound. How old are they? Ocean Forrest should carry you for a while. Has the soil been re-use? What nutes are you running through it?

OK, if you're in plastic pots at 38 days it's safe to pull one out (GENTLY, stop if it's a struggle or root all falls apart easily) of the pot to examine root ball... When having deficiency its nice to be able to just take a quick peek at the roots. Might identify things like root rot, mildew and/or root bound.
At 38 days you shouldn't be root bound.
In soil, pH of 7 (soil pH) is normal. I use soil and organics 100%. My soil rides at 7ph I also feed between 4.7 and 6.5 as microbes in the soil will buffer that pH for me for natural plant uptake.

How do your plants look? Are they telling you they don't like it?

This is the only picture on my phone it's the bottom left one the 2 bottom leaves are yellow and falling off and the set up is starting to get brown spots.

You are describing possible nute lock out (due to pH in soil) or cal mag deficiency is what it sounds like to me. Based on the pH readings you get I would lean more towards ph lockout.
It's possible the microbial colony in your soil has been shocked a bit from eradic pH and/or drying out to much... Throw some mulch on top to retain moisture so colony thrives better. Microbes do not like to dry out. A bit of a double edged sword there... Not to much water, roots need to air out a day or so before more fluids. Adding a ground cover helps here tremendously, especially for us soil and organic growers.
I would flush with 6.5 pH, then top dress with some good organic amendments watered in with a good compost tea. I use "roots organics grow and bloom dry amendments", also use there "terp tea" products for brews and top dressing.
That should bounce you back OK.

Thank you!