On Sat, 26 Mar 2005 11:37:51 -0000, "Gill Passman"
gillspamattaylorpassmanspam.co.uk wrote:


"Dick" wrote in message
.. .
On Fri, 25 Mar 2005 10:51:55 -0000, "Gill Passman"
gillspamattaylorpassmanspam.co.uk wrote:

I'm curious about a variation in pH between two 50 gall tanks that I
have.
Just done the tests and didn't get the result I expected so would be very
interested in your comments. Firstly I didn't expect them to be the same
necessarily but what I got was the opposite to what I was expecting.

1st Tank is a Community Tank full of plants, driftwood, fish and
unfortunately still battling with my algae. Substrate is just standard
gravel. This tank has been up and running since September. Possibly
verging
on being overstocked - plans afoot to move some of the residents into
other
tanks. Readings a-

Nitrates 20
Nitrite 0
Ammonia 0
pH 8

2nd Tank is a Malawi Community Tank - set up around 5 weeks ago and
cycled
using existing filter medium. This has Ocean Rock and Marine Gravel plus
some crushed coral. Only four plants that are holding their own. Still
stocking with fish and it probably hasn't finished cycling yet from the
nitrite reading. Readings a-

Nitrates 5
Nitrite 0.1
Ammonia 0
pH 7.5

I use the same water on both tanks (treated tap water) and do the same
water
changes on both. The pH of the tap water is 7.5.

Now, I would have expected either the pH to be the same in both tanks or
lower in the first tank because of the driftwood. Any ideas? plus might
this
be indicative of a problem in one of the tanks - the first tank does
appear
to fluctuate between 7.5-8.?Or is the difference down to the fact that
the
second tank is still cycling?

Thanks
Gill



I wonder about your water changes, how much and how often. My 5 tanks
have the same pH as my tap water (I change 20% twice weekly).

As for why the difference, I have no opinion. I trust water changes
to solve all problems. g

dick

I do 20% weekly on all 5 tanks and prepare the water in the same way for all
five of them.


Might be worthwhile to do twice weekly changes and see what happens,
if you can find time. Easy for me to suggest as I have more time than
I can handle. g

dick