what is this

appears to be some sort of fungus or mold from the cocanut shell, it could be that the shell is slowly rotting and this is the result of it. I have had this same experience with some drift wood that I had in my discus tank once. just use a soft sponge or scraper and wipe it off shouldn't pose any real prob's though.
 
I guess my pH should be around 10 right now...

My pH indicator reads from 6.0 to 7.6
pH of tapwater = 6.4
So here is what I get,
I use tapwater mix with tank water in the ratio of 5:1
and I get pH of 7.0

my own not so steady formula...

(7.0 - 6.4 ) = 0.6

0.6 x 5 = 3.0

so pH of tank water is 7.0 + 3.0 = 10


I hope someone would just understand what I mean, I am very poor in
describing..:cry:
And I really wonder If that way of measuring pH works
 
I'm no scientemist me, but I don't think that's how it works lol.

For a start, your Ph coming from tap being 6.4 means that unless you had particular substances in the tank which 'buffer up' (rockwork, particular substrates) it won't increase from that baseline.

Certain other materials (driftwood has a small effect) will bring it down, as will increasing nitrates beyond safe levels, as will passage of time.

What are you using as a Ph test (noting that you have a reading of from 6.0 to 7.6 this is a very wide margin and not sufficiently accurate in reality) ?
 
I guess my pH should be around 10 right now...

My pH indicator reads from 6.0 to 7.6
pH of tapwater = 6.4
So here is what I get,
I use tapwater mix with tank water in the ratio of 5:1
and I get pH of 7.0

my own not so steady formula...

(7.0 - 6.4 ) = 0.6

0.6 x 5 = 3.0

so pH of tank water is 7.0 + 3.0 = 10


I hope someone would just understand what I mean, I am very poor in
describing..:cry:
And I really wonder If that way of measuring pH works

pH doesnt work that way, its a logarithmic scale. An increase from 7 to 8 is a 10x increase in alkalinity btw.

You can always look at ebay for a cheap pH pen. Even the cheap $30 pens can measure that range of pH.
 
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