FF Happy Frog Low PH Runoff?

Hey guys, First grow here.

Using:
FF Happy Frog
GH Flora Trio
Diamond Nectar
Liquid Koolbloom
Armor-si
Cal-Mag

Now early one someone I knew told me that with soil, all you need to worry about is what is going IN. and that as long as those numbers are fine.
But recently (day 30-35 of flower) it seemed to be drinking a lot less water in general. I became concerned of nutrient lock. So I decided to test the runoff. PPM was fine (700-1000) but the PH dropped to 5.5! (6.5 going in)

So now, I've run already 2 gallons of PH 7.0 tap water through the soil and it is STILL coming out 5.5?! Is this normal?! It's a 3 gallon pot so I'm going to continue flushing for now hoping it comes up. Could it be the soil that's at such a low PH? Or just a massive salt buildup from lack of flushing ? Please any help you can offer is GREATLY APPRECIATED. I really don't want to have to start testing the soil every grow now as well -.-

Is this a problem I should be concerned about? Since I've been googling I've now found out you can also find out the PH of your soil as well?! Are these 3 things I need to know for every grow? (testing the PH of the soil etc.?) Or can I just keep an eye on the PH runoff and make sure it stays close to feed PH. and if not, flush?

I use FFHF too and never have issues with soil PH. Runoff water PH is not a good indicator of your soil PH.

All the flushing is probably doing more harm than good.

Sounds more ph buffers may be exhausting slightly ..... however you can compensate by recharging mix ( top dress fresh ammended soil HF or FFOF ) - PH 6.5 - 6.7........ or a bit of oyster shell ( down to earth brand ) ( HF / FFOF use oyster shell ).

If you continue to “ flush “ , you will forcibly “ leach “ the soil of elements not targeted. Dilution of medium.
If plant was only slowing in water use , kind of normal and not necessarily an issue. Too easy to wreck a grow by getting heavy handed.

plant pics ?

I had a bad batch of h.f ( to much N ) so now even if the batch is hot I mix mine with their coco loco and never had problems again

Heard that FF products are regional and various sources for elements used in mix , so may be different time to time

Another good simple grow mix is a straight 50/50 blend of HF / FFOF ......
HF / FF are easily tempered with mild soil.