Improve tap water, KH/GH supplement and SALT usage.

[HarryDk]

Hi All,
I read a lot of threads regarding water hardness here but it seem like people have different water and conditions.
I have been very diligent with w/c for the last 12 months on my 500L tank and manage to keep nitrate under 10 most of the time.
I dont do daily w/c due to time limit and I have to age 400L of water every 3 days (80% wc twice weekly) and match temp by 5G buckets of hot water and add extra Prime/Safe.

I always feel like something irritating my fish for a few hours after each w/c which I can not explain ( I can guess that may be because of the small different in PH, before water change PH in tank will be around 6.8 and aged water PH is around 7, or 7.2 in a bad day).
I live in Melbourne where the water is neutral out of tap, but KH/GH nearly zero. I add some rock salt and baking soda each w/c to bring them to 1-2.

I know that many people here do not agree with the regular use of salt for discus but I need some suggestion badly.
What is the best way to maintain stable water, I read a thread about adding a mixture of Sodium Carbonate and epsom salt will increase KH/GH with minimal effect on HP? Would this apply to my case with neutral water and nil hardness? I mean Would I use it every w/c?

PS: extra Q, I rescued a few discus with hex and hole in the head in my hospital tank, treated them with Metro and they are eating/ active again, how long should I wait until move them into main tank? How long for those nasty holes to close? 1 year into discus and I'm still a newb :(

[Kyla]

our tap water has very low kh also, and if i skip water changes my ph will drop steadily as the buffering capacity of the water is used up. more frequent water changes can easily solve this issue but i have a lot of friends who only change water 1x/month (they dont keep discus!) and in their tanks the ph can drop so low it cannot be tested with the api test kit because it is below the lowest colour on the strip. to counter this ph fluctuation/crash, i added a baggie of WELL RINSED aragonite to all of their filters, and i always keep a baggie in my tanks as well. pretty much everyone i know got a baggie for xmas lol! it works, and it keeps on working for a very long period.

dont add too much at once tho, u need only a very small amount and u dont want to raise ur ph. i would start with rinsing half a cup really well and add it bit by bit and test for the next couple days and if u still see ph dropping then add a little more etc until u find ur correct amount. u want just enough that it will hold ur ph stable between wc without raising it.

u want to put it into a mesh baggie with tight weave and rinse that baggie under ur tap squishing it around lots, until no particles rinse out (i put a bowl underneath to catch the sand). u dont want little particles getting in ur filter mechanisms.

putting aragonite in a tank might be contrary to what others here recommend but it has worked well for all of us for years.

all that being said increasing the wc will replenish the kh. i dont think i need a baggie in my filter anymore but i keep it there just in case.

[Clawhammer]

our tap water has very low kh also, and if i skip water changes my ph will drop steadily as the buffering capacity of the water is used up. more frequent water changes can easily solve this issue but i have a lot of friends who only change water 1x/month (they dont keep discus!) and in their tanks the ph can drop so low it cannot be tested with the api test kit because it is below the lowest colour on the strip. to counter this ph fluctuation/crash, i added a baggie of WELL RINSED aragonite to all of their filters, and i always keep a baggie in my tanks as well. pretty much everyone i know got a baggie for xmas lol! it works, and it keeps on working for a very long period.

dont add too much at once tho, u need only a very small amount and u dont want to raise ur ph. i would start with rinsing half a cup really well and add it bit by bit and test for the next couple days and if u still see ph dropping then add a little more etc until u find ur correct amount. u want just enough that it will hold ur ph stable between wc without raising it.

u want to put it into a mesh baggie with tight weave and rinse that baggie under ur tap squishing it around lots, until no particles rinse out (i put a bowl underneath to catch the sand). u dont want little particles getting in ur filter mechanisms.

putting aragonite in a tank might be contrary to what others here recommend but it has worked well for all of us for years.

all that being said increasing the wc will replenish the kh. i dont think i need a baggie in my filter anymore but i keep it there just in case.

Hi Kyla, I have no KH out of my tap as well. I add about a tbsp of baking soda per 50 gallons of new water and also have crushed coral in my filter. Why do you prefer aragonite? Thanks!

[Kyla]

aragonite is the crushed coral available at my local pet store. how much aragonite do u have in ur tank? do u find u still need to add baking soda even with the aragonite?

[Clawhammer]

aragonite is the crushed coral available at my local pet store. how much aragonite do u have in ur tank? do u find u still need to add baking soda even with the aragonite?

I have a couple handfuls in one of my canister filters. I have found that the CC didn't keep the pH stable by itself, but did slow down the pH decrease. Using baking soda as I described provides immediate KH and keeps my pH firmly in place. I have 6.7-6.8 pH out of the tap.

[HarryDk]

Thanks for your reply Kyla,
How about GH? I have been using rock salt.
I read this thread and it said Calcium Carbonate can increase both KH/GH, has anyone actually use it?
http://forum.simplydiscus.com/archive/index.php/t-21166.html

[DJW]

Crushed coral and aragonite are calcium carbonate -- same stuff. When it dissolves it adds both GH and KH to the water equally. The calcium contributes to GH and the carbonate contributes to KH.

If your pH only falls to 6.8 in three days, either one should work. As Kyla mentioned, you have to experiment to find the right amount. Rock salt is the same as kitchen salt. It will add to the TDS but won't increase GH or KH.