Yellow Leaves with Brown Spots!

I am a total noob to growing this is my first grow. I’m now a week and a half into flowering and up to now not had no problems. Generally my temps are 22c min - 28c max and humidity is 45% min and 75% Max. Then the other day i looked and stated to notice that my leaves were looking a little dry and just starting to turn up at the ends. Then the odd couple of leaves turned yellow with brown spots. I initially thought maybe i was feeding them too much so then i would be giving them to much nutes so i thought they had nute burn. After flushing them with just water for a week no luck its still here someone please help any suggestions?

Looks like you've got mites and PH lockout (unless you don't feed them, lol). Flushing will help with the ph, but you'll need some neem oil or other pesticide that's safe for fruits and vegetables to kill the mites. 75% r/h is pretty high, do you have a de-humidifier? I don't think you've got mold, unless you spray your plants a lot.

Dropping your temps will help slow the mites reproductive rate, which is every 3 days under your conditions.

hotshot from home depot will rid those mites leave the hotshot in for 4 days. Ph issue i agree. I dont really know much though

would these mites be visable because i have had a very good look around them and cant see no bugs? also would be the best precidure with ph lockout?

Mites are hard to see even with a magnifier, what we saw was the damage they do to the leaves.

Flushing your soil is best for ph problems. Flush with 2-3x pot size eg, 5 gallon pot flush with 10-15 gallons water. I put my buckets in a 40 gal rubbermaid and flush with tepid water until bin is 1/4 full. I use a small water pump ($10) and a storage bin for a reservoir.

thanks for the advice i will carry on with the flushing, and purchase something to tackle the mites.

would you know what type of mites these were? also when im looking for spray its seems like its always for spider mite is this ok to use for my dialema? Also i was given ionic Grow A, and B Hydro from a friend not realising i had soil setup. I used it for a week then chaged it when i seen it was for hydro, would this of effected my plants?