Calcium Deficiency?

I just noticed a handful of small brown spots one one of my plants.
Is this the start of a calcium issue or maybe something else?

I'm about to feed it as it's almost dry, I watered a week ago with ph'd water after transplanting from 1 gallon to 7 gallon.
Will be giving it nutrients today, the part 1 base has 5.5% calcium.

About the watering, is a week or more too long for it to go between watering? I soaked the pot until there's runoff.
I wait until it's pretty dry before watering again.

Indoor/container soil grows are not what I do the most of, but I have found that lifting the container is a good weigh(like that???) to judge when it's time to water.
I've always used my hydro nutes mixed into the amount of water I'm going to give to my plants for that watering. Always seems to give me good growth and no weird issues.

Thanks GBAuto. I’m using promix hp medium. No fertilizer in the soil so everything comes from the water. I guess transplanting into the 7 Gallon pot and only giving water it was lacking calcium for the past week. I have very soft water with next to no calcium. The feeding I gave today should give it a calcium boost.

FWIW I'm using the Root Farm nutrients. Part 1 is 4-0-1 and has 5.5% calcium. Second part is a 1-5-7 with 2.2% Mg and 2.8% sulphur.
I'm using a 2 tsp of a 1 of b for now to get roughly 2:1:2 - I researched a bit and figured at the price point it's a good place to start. I've seen comparisons to Sensi grow. I

In case anyone comes across this it's most likely calcium - I found another post where the pictures are identical and they had a calcium deficiency.