Will a GH/KH shift affect fish?

Bawb2u

Gambusia
MFK Member
Nov 21, 2005
292
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MA
Our water supply is VERY soft with minimal GH and no KH to speak of. The problem is, with the way our town treats our water it can come from the tap at up to 9.0 PH! I've found that letting it age for 48 hours or so, it'll drop down to 7.2 and pretty much stick there. That is, until you start adding driftwood and waste, which, since there is no Gh or KH, will cause the PH to just plummet in a heartbeat, going as low as 6.0, which is the bottom of my test kits limit. Definitely not good for the fish, especially as the PH would yo-yo by doing water changes.
By experimention, after reading a formula I found on the internet for African cichlids, I've concluded that by adding 1 TBSP of Epsom salt, 1 TSP of marine salt and 3/4 TSP of baking soda per 5 gallons of water, I can get my GH to about 80 ppm, my KH to about 90 ppm and my PH to about 7.2 with no measurable salinity by hydometer.

So the big question is, do you think a large shift in GH and KH but not PH will cause any affect to the fish?
 

Dr Joe

Feeder Fish
MFK Member
Mar 8, 2006
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Yes, but the severity depends on the fish. Best to change things slowly (as in over a month's time).

In the mean time build up some pre-treated water and store for W/C's to make life a little easier.

Dr Joe

.
 

HarleyK

Canister Man
Staff member
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Aug 17, 2005
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Howdy,

:iagree:

Pre-mix and then add to your tank, not add water and then salts. You will need holding barrels. But an increase in hardness is a great idea and highly recommendable to prevent pH crashes!

HarleyK
 

Bawb2u

Gambusia
MFK Member
Nov 21, 2005
292
2
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MA
HarleyK;2024690; said:
Howdy,

:iagree:

Pre-mix and then add to your tank, not add water and then salts. You will need holding barrels. But an increase in hardness is a great idea and highly recommendable to prevent pH crashes!

HarleyK
I have a 75 gallon holding tank I use for ageing my water any way, so I'll definitely do it as a pre-mix. I'm also planning on doing like Dr. Joe suggested, I'll do half mixes in the 75 for the first couple of weeks, doing 70 gallons a week in a 180 gallon tank for the first month, maybe two to be on the safe side, doing my continual tests and then ramp up to the full dose, adjusting for the tanks parameters at that point.
Tank will be home to one fish, a fahaka puffer.
 
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