230 Litres Aquarium Water Problem PH

[migdem]

Hi all,
I have a 230 litre aquarium and have a problem with the water.

I do 25% bi-weekly water change but PH is extreemly low.

Water parameter from aquarium :-

GH - 6
PH - 5
N03 - 50
no2 - 0
kh - 3


Water parameters from tap :-

GH - 3
PH - 9
kh - 3

The problem is that the PH is always low and cannot keep community fish in the aquarium.

In the tank I only have pebles as gravel, few plastic plants and one petrified wood. These have been there for some time now.

Filter I have Bio-Home, Eheim Ceramic (10 years old never changed but cleaned), cotton and coarse filter.

When i do water change i syphon the bottom so that it always be clean.

How can i arrange this sittuation?

Thanks

 

[Nyghtfire]

if your willing to change the substrate there's alot of gravels about that raise the ph.
i wouldn't recommend chemicals.
certain types of rock will do it although someone else would have to help you there as i'm not sure.

 

[migdem]

Well the problem is that I do not know why the PH drops so low from WC since from tap water it is 8.

What type of gravel are you referring to?

 

[migdem]

bump