Hi Everyone,

new to this forum and I'm fairly new to goldfish keeping.
I have a new-ish pond ( about 180 liters )which has recently cycled, and plan to put 3 goldfish from a much smaller pond (about 80 liters capacity) there in the near future.
Problem i'm having is in raising the hardness level of the water in the new pond. The water out of the tap in my part of the world is very soft ( only about 3 deg. ), so I have used crushed coral in the (small) pond which has kept the GH at about 10 degrees.
In the new pond I have opted to use crushed aragonite, rather than coral ( was told that aragonite would dissolve faster than crushed coral in a ph of 7.5-7.6 ). And I'm having trouble raising the GH above 5 or 6 deg, using the crushed aragonite.
I have about 4 filter bags each with about 250 grams of the aragonite, and spread the bags around the bottom of the new pond.
Started off with just one bag, and have increased to the current 4 over about a month. I test every week but the GH just won't shift.
I have the pump running 24/7 so there's plenty of surface action, there's no rainwater or leaves getting into the pond, so nothing to make the water "soften". I'm wondering if I should be using alot more than the 1kg aragonite which is in there already ?
Reason that i started with small-ish amounts is that I was warned using too much would cause the PH to jump..This hasn't happened, however. PH is still at about 7.5 or so, same level as the small pond.
No idea how much aragonite I can use as the packaging gives no idea and the local fish shop simply said it was a "trial and error" system.
Any help would be greatly appreciated !