My struggle with PH levels.

Hey guys,
I made a couple of threads a few weeks ago about some problems I was having with my seedlings, and with some advic from you guys and a lot of experimenting I think I found my main problem.

I'm not a first time grower but this is my first time growing from seed and my first time using coco/perlite/verm mix.

The coco I used was in brick form and supposedly ph neutral, so I just put it in a bucket and filled with the right amout of PH corrected RO water, added the perlite and vermiculite and proceded to propergate my seeds.
Then the problems started(see my other threads), I tried everything and managed to save enough to get me going.

The other day I decided to check my run off when I did a flush, and to my suprise it was very low, and it was very red in colour.
so I check the others and find the same. I have only feed them on a very week nute diet

so next I get some more coco mix and I rinse the crap out of it until the run off is clear. I planted some more seeds in this cleaned mix and they are going great.

My RO water and tap water are very high PH (is this normal?) so I am having to add heaps of PH down.
After i get the right PH reading I wait an hour or two and test again, I find that it keeps going back up and I have to add more PH down. I mix up my tank and I have air stones so I dont think it's the nutrients settling down.

I cant wait to get through this grow and go back to using clay balls.

And another lesson I just learned, computer fans dont have a protection guard, ouch!

No, it's not normal for your tap or runoff water to be so acidic. Are you using a meter to test your ph if so I would make sure it's calibrated correctly. Some meters are really cheap and inaccurate. I use the drops myself never a problem.

yeah I use the drops to test. I will buy some bottled water and another brand of test drops and see what results I get. I might test some water from peeps I know around this area too.

I live in a very old house, maybe my pipes are farked.

To start with get a new meter(or calibrate the old one) that sounds strange that ph goes up after youve corrected it. I also have high PH water and i use canna nutes which makes the PH 6.5 every time(buffers) and i dont bother testing every feed now and have green leaves top to bottom at harvest. I still PH waterings though. Dont be to concerned measuring run off just the feeds/waterings .

Sorry just realised its hydro, to reduce chances of PH jump get a bigger res and nutes like canna with buffers.