Ph Dropping

[Joller]

I've had my tank set up for about six months, my tap water is pH7.4 and i do a weekly 33% water change.
but over the past month or so the pH has slowly been dropping and now its about 6.4. all other water stats are fine.
I've slowly been accumulating pieces of bog wood and i understand that this lowers pH quite a bit, so i took them out and did a water change yesterday and since then the pH has still been dropping (was back up to 6.8 yesterday and now 6.4 again)
(i also have 2 anubias plants, 1 large 1 small)

now i remember being told when i first started setting up the tank that i shouldn't mess with pH up chemicals, but i'm starting to consider it.

does anyone know why my pH is dropping? and also why pH up isn't a good idea?

 

[Curiosity101]

Don't suppose you know what your kH and gH vaules are?
This would help in advising how you should progress

Reason 'chemicals' aren't recommended is because pH up is basically like dumping an alkaline solution into the tank. It is temporary and expensive...so leads to further fluctuations in pH unless you want to add it EVERY time you notice the pH change more than say... 0.1 or 0.2

 

[WILDER]

What's your tap ph.
What substrate and ornaments do you have in the tank.

 

[Joller]

yeah i'll steer clear of the pH up then.
tap pH is 7.4
the tank has small pebbles as substrate. ornaments are just some garden pottery and a few plastic statues.
i know kH is hardness, how does it effect pH? and whats gH?

 

[Joller]

i just read that sea shells and corals are a good means to increase pH slowly, i have heaps of shells lying around the house so i might give that a try.

 

[Curiosity101]

GH is a measure of how much calcium and magnesium is dissolved in the water, but often it isn't pure calcium or magnesium that has been dissolved. More often than not it's things like calcium carbonate etc.

KH is the Carbonate Hardness of the water, and is a measure of how much acid your tank water can absorb before the pH changes. Crushed coral dissolves overtime to give you calcium carbonate. This increases GH and KH
And therefore raises PH AND keeps it more stable.

The reason it's preferred over the liquid pH up and such is because it is a slow and constant rise. So you wont cause PH shock to your fish, but you will get the desired results.

Also particularly with API PH Up it contains Sodium Carbonate...and I don't think it's particularly recommended to add extra sodium to the aquarium. Plus for how much it costs you to buy, if you really wanted to use it then you may aswell buy baking soda and dissolve some at home.
Fraction of the cost, and you'd have a lifetime supply, as opposed to a bottle that would last a matter of weeks.

But like I said, extra sodium isn't a good thing, neither is the risk of PH shock when you have good long term (slow acting) alternatives such as crushed coral.

If you are going to go down the crushed coral route then please be careful if you're using shells from your house. You need to make sure they haven't been treated with any glazes or paints. And that if they are from the sea side that they have been thoroughly washed to remove salt.

 

[Joller]

yeah i got them from the beach ages ago. surely such a small amount of salt wouldn't harm cichlids?
i plopped 2 large sized pipi shells in last night. i'm not even sure if that will be enough. water change today =)