(GH) Hardness Concerns

aquariumfishguy

Social Regular
Jul 14, 2003
1,839
0
0
58
Michigan, USA
www.care4fish.com
In my 55 gallon goldfish tank, I have 3 fantails. It has been set up and running for over 10 years now. Anyway... today I was doing water changes and on this 55 gallon tank, I noticed the total hardness (GH) was high. Based on the reading I took, I am guessing it is around 200 ppm.

The water I use for water changes (via a python) has a GH of about 15-20, which as many of you know is very soft.

... So, my question: why is the water in my aquarium suggesting that my GH is about 200 ppm? Can something in my aquarium throw this off? I have never had to deal with such a problem before, if having a GH of 200 is even a "problem".

Please help.
 
Possible high evaporation with build-up from make-up water? Possible calcium/magnesium bearing substrate with some degree of solubility? Shells as ornament in the tank? High-calcium foods (that is a bit of a stretch)?
 
I do have some shells in my aquarium, mixed in with the gravel. They are shells I picked up on the beach in Northern Michigan. Could this be the main source for why my GH is so high?

Also, is it a problem for my Goldfish? My water is normally pretty alkaline anyway... but overall hardness is pretty soft.
 
The KH is 190 in my aquarium, and it is the same at the tap. Like I said, my tap water is pretty soft itself, so this level made me wonder if it was the shells. I have had them for years, and never tested hardness in this tank... I just assumed ignorantly enough that they would be fine.

In my head I am going back and forth on whether or not I should remove the shells. I do not have that many, but they are enough to be a pain to dig out.
 
I really doubt that is worth the trouble to clear them - you are still in the comfort range for goldfish. Just remember if you have to move any to an alternate tank that you need to do a slow acclimatization to avoid possible osmotic shock from likely osmotic differences between that tank and fresher tap.
 
Thanks for your help and thoughts on this. It is a big relief...

Any time you do a test like this one and find such a big difference in your aquarium water in comparison to your tap, it makes one think a little. :)
 
AquariaCentral.com