Effect of PH water on soil question

Hey rollitup community!
I just wanna ask because it's becoming more and more confusing for me the effect of PH in water and its effect on the soil/or in the soil

So basically, when you water, if my water is at a PH of 8, and I water my plants (soil) then what effect will that have on the soil and vice versa
Will it decrease acidity of my soil if the PH of my water is HIGH.

All I'm asking is, if my soil has a high PH, should I water it with low PH water or high PH water? And, specifically the numerical/statistical side to this please.
For example, SOIL PH 7.5 + WATER PH 5.5 > It will decrease soil PH to 6.3 or something like that, anyone know the exact kinda calculation?

The PH of my soil is unknown to me, my PH soil meter aint working even after just buying it...
Anyways I recently fertilized it with organic seaweed extract and didnt adjust the PH after mixing, and now i'm getting brown on the leaves and possibly stunted growth.

Please help

the ph of the soil has less to do with the ph of the stuff you pour into it than it does with the general health of the soil and its ability to buffer itself. organic fert-type products should not require "ph-ing" because adjusting them with chemicals sort of defeats the purpose. generally the soil would be amended with something like dolomite lime prior to planting to avoid ph issues altogether (and also have a nice dose of cal and mag). most quality soils come "ph balanced" although the effectiveness of the liming agents they use can be debated. pouring fluid that has been ph'd to any extreme (acid or base) will serve more to screw up your soil up than to fix it.

if you poured seaweed fert and then got brown leaves, i'd bet there's something else going on besides ph, unless the soil was a mess to begin with, or you used some crazy amount.

what type of soil is this and how old are the plants? what type of seaweed fert and how much did you use? have you fed them anything before?

and pics pics pics. a picture really does say a thousand words.

Thanks a load mate for the insight and information.

Here they are on the 28th of May, which is Day 12 of vegetation
I fed them with full strength organic seaweed extract when it was like Day 8-9 and I started getting these problems
Its a New York City Diesel
View attachment 2198506View attachment 2198507

These are my plants now at Day 19 , 5 days into flowering
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Its 3x24watt CFL warm white, 12/12 , watered them after that pic