Regarding General Hardness (GH) in a planted aquarium with tropical fish

[mega_newblar]

Can someone check my logic here?

Definitions:
PH = Percent Hydrogen
GH = General Hardness (measured in dH)
KH = Irrelevant
dGH = Degrees General Hardness
dH = Degrees Hardness
TDS = Total Dissolved Solids
PPM = Parts Per Million

33 Gallon Aquarium Information
Current PH: 6.2-6.4
Target PH in the future: 7ish
Current GH: near 0
Current KH: near 0
Target GH after this water change: 1dGH
Future Ultimate final/target GH: 6-8dGH

Seachem Equilibrium, my GH increaser, says to use 16g or 1 tablespoon for every 20 gallons to raise the GH by 3dH.

"To raise mineral content/general hardness (GH) by 1meq/L (3dH), add 16g (1 tablespoon) for every 80 L (20 gallons) when setting up an aquarium or when making water changes (add to new water)."
-Word for word instructions from the label

I have a 33 gallon tank, so if we cross multiply and divide to get a proportionate ratio I come up with a total requirement of 26.4g of Seachem Equilibrium to raise my 33 gallon tank by 3dH.

Work:
16g = 26.4g
20gal = 33gal

(16x33) % 20 = 26.4

I only want an increase of 1dH, so I divide 26.4g by 3 to get 8.8g. That means 8.8g of Seachem Equilibrium raises my dH by 1 for a 33 gallon tank.

So,

1) It doesn't matter how much water I add the Seachem Equilibrium into? All I consider is the ultimate tank size, 33 gallons.

2) Considering these fish have never had any hardness in there water, is increasing the GH by 1dH per day too severe? Should I raise it by 1dH every other day? Should I raise it by .5dH?

3) Is it true that dGH can be found with a TDS meter by utilizing the following formula:
PPM = dGH * 17.9
dGH = PPM % 17.9

And if so wouldn't that make my GH kit useless, as I have a TDS pen?

4) I have the following fish and lots of plants. Based on the following table I think an ultimate dGH of 6-8 would be ideal. Or does that not matter as much? As long as its close?
Lemon Tetra
Pristella Tetra
"White Cloud" Mountain Minnows
Zebra Danios
Blue Neon Tetra
Kuhli Loaches
Corydoras Julii Catfish
Zebra Horned Nerite Snails
Amano Shrimp

0 - 4 dGH 0 - 70 ppm very soft
4 - 8 dGH 70 - 140 ppm soft
8 - 12 dGH 140 - 210 ppm medium hard
12 - 18 dGH 210 - 320 ppm fairly hard
18 - 30 dGH 320 - 530 ppm hard
over 30 dGH over 530 ppm very hard



Thank you for any information.

 

[Caliban07]

Can someone check my logic here?

Definitions:
PH = Percent Hydrogen
GH = General Hardness (measured in dH)
KH = Irrelevant
dGH = Degrees General Hardness
dH = Degrees Hardness
TDS = Total Dissolved Solids
PPM = Parts Per Million

33 Gallon Aquarium Information
Current PH: 6.2-6.4
Target PH in the future: 7ish
Current GH: near 0
Current KH: near 0
Target GH after this water change: 1dGH
Future Ultimate final/target GH: 6-8dGH

Seachem Equilibrium, my GH increaser, says to use 16g or 1 tablespoon for every 20 gallons to raise the GH by 3dH.

"To raise mineral content/general hardness (GH) by 1meq/L (3dH), add 16g (1 tablespoon) for every 80 L (20 gallons) when setting up an aquarium or when making water changes (add to new water)."
-Word for word instructions from the label

I have a 33 gallon tank, so if we cross multiply and divide to get a proportionate ratio I come up with a total requirement of 26.4g of Seachem Equilibrium to raise my 33 gallon tank by 3dH.

Work:
16g = 26.4g
20gal = 33gal

(16x33) % 20 = 26.4

I only want an increase of 1dH, so I divide 26.4g by 3 to get 8.8g. That means 8.8g of Seachem Equilibrium raises my dH by 1 for a 33 gallon tank.

So,

1) It doesn't matter how much water I add the Seachem Equilibrium into? All I consider is the ultimate tank size, 33 gallons.

2) Considering these fish have never had any hardness in there water, is increasing the GH by 1dH per day too severe? Should I raise it by 1dH every other day? Should I raise it by .5dH?

3) Is it true that dGH can be found with a TDS meter by utilizing the following formula:
PPM = dGH * 17.9
dGH = PPM % 17.9

And if so wouldn't that make my GH kit useless, as I have a TDS pen?

4) I have the following fish and lots of plants. Based on the following table I think an ultimate dGH of 6-8 would be ideal. Or does that not matter as much? As long as its close?
Lemon Tetra
Pristella Tetra
"White Cloud" Mountain Minnows
Zebra Danios
Blue Neon Tetra
Kuhli Loaches
Corydoras Julii Catfish
Zebra Horned Nerite Snails
Amano Shrimp

0 - 4 dGH 0 - 70 ppm very soft
4 - 8 dGH 70 - 140 ppm soft
8 - 12 dGH 140 - 210 ppm medium hard
12 - 18 dGH 210 - 320 ppm fairly hard
18 - 30 dGH 320 - 530 ppm hard
over 30 dGH over 530 ppm very hard



Thank you for any information.

The logic in your definitions is sound except that KH is irrelevant as this is the measure of carbonate hardness which directly effects how resistant your water is to pH change which is very relevant. High KH = more resistant and low KH = low resistance and more likely fluctuations in pH.

KH is also important for the proper functioning of nitrifying bacteria.

Your math looks correct for your tank and I would agree that changing any parameter slowly is always going to be better as far as the tank inhabitants are concerned.

It's true that 33uS = 17.9ppm which is very loosely = to 1dGH.

The reason I say loosely is because well TDS meters measure conductivity and not total dissolved solids. Conductivity in the sense that they measure ions (charged molecules) however not all dissolved solids have a charge. For example a cup distilled water with a spoon of salt will have a high TDS using a meter where as the sugar will not register yet they very may well have a similar amount of total dissolved solids. The true way to measure the dissolved solids in this case would be to evaporate the water and measure the weight of the remaining solids of each cup.

So here we already have a discrepancy in our measurements. What's worse is that gh is the measure of divalent metal anions which are mostly calcium (but there are others) and magnesium and has no real relation to TDS because TDS is all dissolved solids.

Couple this with that fact that liquid test kits for gh and KH and not overly accurate to begin with you begin to wonder why you started this hobby in the first place ?.

Which brings me to my next point. Unless you have specialist fish or fish that require certain parameters in order to spawn you don't need to worry about ph, gh, KH or even TDS. You just need stable water in nearly all community freshwater aquarium cases. Simply adding some crushed coral to your filter will raise your KH and keep ph more stable. Tap water usually has a decent supply of calcium and so adding a touch of magnesium sulphate as a dry salt will help raise magnesium if you are overly concerned.

Bottom line is don't other think this stuff.


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