"Jamesy" wrote in message
s.com...
Hi there

I have a new tank set up for Mbuna, which has been cycling nicely for
several weeks now.

Specs are :-

Juwel Rio 300 tank (300 litres, I reckon about 220 really, taking into
account displacement)
"African Cichlid Mix" gravel substrate
50 lbs of Tufa rock
Juwel "Jumbo" internal filter
Eheim Pro II Thermo 2128 external filter
2 x 38w Juwel "Multilux" lights
300w Juwel heater (plus Eheim thermo)

Ammonia 0
Nitrites 0
Nitrates 5
pH 8.2
GH 100 mg/l
KH 200 mg/l

I am currently keeping the temperature high at around 30 degrees, as I
have
heard that this encourages bacterial growth.

My problem is water hardness!

The tapwater here (Central Scotland) is very soft, and I'm trying to
raise
the hardness. The combination of the substrate & Tufa rock have raised
it
slightly, but I don't expect miracles from it - it's primarily as a
buffer
after all. I have added some Interpet Water Hardener, to very little
change.

However, my problem really isn't the hardening of the water - I can
simply
keep adding hardener until it's hard enough, right? But what's going to
happen to my pH level?

What really confuses me is the relationship between the pH and KH
levels.
Everything I've read has indicated that a high pH level can "usually"
be
associated with a high KH level. However, our tap water is very soft,
but
slightly alkaline (around 7.5), and now my tank water has a pH around
the
right level, but is still too soft. What can this be attributed to?

Am I worrying too much? Is my current KH/GH level sufficient for
(presumably) tank-bred fish? Should I just chill and forget about it?
Should
I have listened more in Chemistry class 20 years ago?

At first I thought you made an error with your measurements (kH gH?)
but then I read about your chemistry. My advice? chill.

You have 2 main things happening:
1) The tufa and the substrate are going to leech calcium carbonates into
your water (pH goes up or stabilizes, and your gH & kH go up).
2) You are going to do water changes and you will dilute your 'harder'
water with soft water, dropping your gH, kH and possibly your pH.

You have 2 secondary things happening:
3) Fish waste acidifies your water (dropping kH)
4) You gravel vacuum and water change, removing the source of
acidification (kH stops dropping, pH stays stable).

You want to achieve balance (your fish want stability), so your job is to
be consistant with the water changes. If you are doing 20% a week, then
try to always do about 20% every 7 days. Whatever your schedule, stay
consistant. This will cause your water to settle into a narrower range
of parameters

You can check your pH, gH and kH just before a water change, and then a
few hours after. This gives you a comparative reference. Whatever it
settles on will probably be better than anything you would get adding
hardeners, baking soda, liquid calcium, pH up or any other chemicals
(making everything bounce around). Generally, chemicals are bad (imo),
so use de-chlor (a chemical to get rid of another chemical), and avoid
the rest. They are fundamentally flawed because of a fish's requirements
for stability and the average hobbyists inbility to provide stability
through chemical intervention (requires a holding tank for pre-mixing and
complicates your maintenance).

Oh, and one last question! We're going on holiday in about 2 weeks, so
obviously this isn't the right time to start adding fish. Should I
"seed"
the tank with some food whilst we're away, to keep the bacteria alive?

Good idea. A few frozen cocktail shrimp will do nicely.

PS: the bacteria you get will match your conditions (logical eh?), so set
your temperature to where you will be keeping the tank, and stop dropping
chemicals in there.
--
www.NetMax.tk

TIA

--
Jamesy
__________________________________________________ __________