Ph keeps droping????

[axl]

Hi,
I normally run my ph at 7.0 and over the last week the ph keeps going down to 6.5. The kh out of the tap is very soft around 2 and the ph is 6.8 and i dont why this is happening is it becuase the kh in my tank is to soft hence why its not stable. the tank has been setup for nearly 2 years now. Do i need to add bi carb soda slowly to get the kh up to 5 and keep the ph at 6.7 ????? will this make it more stable???

Cheers Axl

[ILLUSN]

whens the last time you gave the substrate and filters a goos clean? a build up of organic matter in both the substrate and filters will lead to ph drops.

a KH of 2 will be hard to keep neutral, instead of adding sodium carbonate try adding crushed coral to either the filter or substrate, you'll get a much slower seep of CO3 which will help keep your kH up, maybe shoot for a kh of 5-6.

[axl]

Thanks for the reply, will give the filters a good clean this arvo and add some crushed coral to the filter. Whats the best way to clean your substrate if you have a planted tank. Do you mean just clean the top of sand as i dont want to disturb the eco complete to much.

[ILLUSN]

Do you mean just clean the top of sand as i dont want to disturb the eco complete to much.

that could be your problem after a few years organic matter (dead roots uneaten food, byproducts of things living in your substrate) can build up and make the tank acidic, try the filter and the coral first, and a VERY light gravel vac of the top 10-15mm of the substrate. if you still get ph drops you might have to give the substrate a deep clean witht he gravel vac.

[axl]

Yeah right, i cleaned both my filters yesterday and they were dirty as so i added some crushed coral to both of them. I am slowing making my kh higher its currenlty at 3 and i will try and get it to 5, plus my ph has stabilised its currently at 6.9. I will maintain it at 6.8.
I purchased a new ammonia test kit today and my tank has 0.25 of ammonia, is this a concern??? I checked my tap water and it was 0 so i added some seachem prime to try and remove it.

[ILLUSN]

the constant droping of your ph knocked around your filters then the big clean shook them up further, add the prime and let your plants soak up the am,monia i dont think you'll have any problems