I am looking for someone with a Malawi tank to do a little experiment for me.

If you are using tap water of a ph of 7 or less for your water changes i am looking for some info.

What substrate and rocks are in the tank?
What is the volume of the tank?
How much water is been changed?
What is the ph in the tank before a water change?
If you have a ph meter can you do a large water change, test the water before adding to the tank and then monitor the ph change in the tank.
How long dose it take for the ph to reach the desired level in the tank?
Also any other water parameter's like KH,GH and Nitrate would be a bonus.

So if some one has the time to do this it would be much appreciated.
I dont keep Malawi's so i cant do this my self.

Darren.

Hi I've a Tanganyikan set up so its close to the same parameters as a Malawi setup so i've tried your little experiment and heres the results

ph from tap 7.2, kh 16 gh 3

substrate Coral sand... later added eco-complete african cichlid sand to boost ph to the 9.3 mark
Rocks Coral rock, and granite and limestone mixed rock

Tank Volume is 180l
change of 10-15% of water weekly
ph before water change 9.3 kh 28 gh 9

after water change dropped to ph 8 kh 19 gh5
befor adding eco complete it would take about 2.5 - 3 days to get to ph 8.3 kh 22 gh 7 so added the eco complete and it buffers it at 8.5 so not too much of a change similar to a heavy storm in natural environment.. generally ph rises back to 9.3 in a 1 - 1.5 days along with kh and gh

hope this helps
seamus

Cheers Seamus. I realy appreciate the time you put into this.
The only way i could have done it was in a 10L bucket.

I wanted to see how quick the ph would rise. I am surprised it took 1-1.5 day's. I imagined it would have been quicker. But now i know.

Thanks again, Darren.