need hardness help

[gingerbeer01]

As per my previous post my tap water hardness is gH 120 kH 80, rain water gH 40 hence mix of 50/50 in my breeder tank gae me gH 100 kH 50.

Tested today and my water conditions are gH 80 kH 180.

What is driving my kH upwards?

Steve

[Th0mas]

Is the tank bare? Any decorations?

Have found certain Terracotta pots does drive the pH up, therefore kH is being buffered by it.

Thomas.

[fishgeek]

kH by definition can not be higher than gH
also as i mentioned in another post your readings seem way off to me as i cant see results with values that high for the readings you are presenting

Hardness is measured in degree's - it is a very old system that shouldn't be used anymore but seems to persist in the aquatic hobby
kH is carbonate hardess
gH is general hardness and is the sum of kH and other dissolved products , hence why i say it shouldn't be less than kH

how are you measuring these?
are the results actually in more correct/modern units ie ppm or mg/l something a bit more scientifically accurate than german degree's of hardness

kH or carbonate hardness is a measure of dissolved carbnates , therefore something is leaching carbonate into your water
limestone or other chalky substrate materials
prehaps acid test your substrate and tank decor, if it fizz's bubbles when placed with acid this wuld suggest that it is likely to be your carbonate source

andrew

[gingerbeer01]

Am using a test kit - Nutrafin brand. The measurements are in PPM.

There is no substrate - but were terracotta pots - so I have removed these. Replaced with rocks. Like the tanks better now and more natural looking caves.

As for the gH being lower than the kH - hmmm. I should have remembered that. Will test again later and post results. pH is testing neutral.

Thanks Thomas and Andrew.

[gingerbeer01]

Now testing gH 80 kH 50ppm that suggests test before was contaminated. I am not sure ( as I can't remember) how well I rinsed the test tube. Is it possible that residue from the gH test affected the kH test.

End result is I will sleep well knowing my opals are in OK water - and I like the decor of the tanks better now as more natural :P

But will be harder to catch out fish without stripping tanks. :roll:

Steve

[wickedglass]

as concerns terracotta ... the more/higher terracotta is fired, the more yellowy it gets. the deep orange terracotta is therefore not as vitrified as the more yellow looking terracotta and is therefore more prone to leaching various undesirables into the surrounding environment. In the garden this doesn't matter, but in a closed system like an aquarium, the leached minerals, etc, can accumulate rather quickly. I use terracotta, but I always go for the stuff that was fired at higher temps and has a more yellow hue.