# [Wet Thumb Forum]-The right way to raise GH??



## Laith (Sep 4, 2004)

I've been noticing that my tap water KH has gone down drastically over the past 6 months; from a high of around 15 to 5 or 6 these days. I usually don't measure GH but when I did and got a reading of 0 (actually the color changed after 1 drop so it could be between 0 and 1) I thought the GH test kit was off. 

Today I spoke to my lfs and they said that the local water supply had gotten a lot softer. Also I've noticed that some new leaves, especially on my Alternanthera plants, were growing very small and crinkled and growth in general has slowed down.

So, the good news is that I no longer need to use RO water . The not so good news is that I need to raise the GH of my water ... 

My tank currently has a KH of 3.5, GH of 0, pH of 6.6. I'm dosing ferts and nitrates via KNO3. CO2 injection with a pH controller and 125w of flourescents (5x 25W) on a 200L tank.

Off I went to the pharmacy and found a Magnesium+Calcium product (produced from a "dolomite sand from Norway...). It comes in the forms of pills, each of which contains 100mg of Calcium and 60mg of Magnesium. As I didn't want to raise the KH, I didn't want to go the Calcium Carbonate (CaCO3) route. 

So, according to my calculations, 15 of these tablets will raise my GH by 1.05 (200l aquarium)? This based on 1 GH being 7.14mg/l of Calcium? 

Therefore if I add 30 tablets, that will raise the GH by 2.1 and will add 9mg/l of Magnesium. 

Could someone please double check my calculations and I'd also like to know if that level of Magnesium in the aquarium is OK? 

Many thanks!


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## Laith (Sep 4, 2004)

I've been noticing that my tap water KH has gone down drastically over the past 6 months; from a high of around 15 to 5 or 6 these days. I usually don't measure GH but when I did and got a reading of 0 (actually the color changed after 1 drop so it could be between 0 and 1) I thought the GH test kit was off. 

Today I spoke to my lfs and they said that the local water supply had gotten a lot softer. Also I've noticed that some new leaves, especially on my Alternanthera plants, were growing very small and crinkled and growth in general has slowed down.

So, the good news is that I no longer need to use RO water . The not so good news is that I need to raise the GH of my water ... 

My tank currently has a KH of 3.5, GH of 0, pH of 6.6. I'm dosing ferts and nitrates via KNO3. CO2 injection with a pH controller and 125w of flourescents (5x 25W) on a 200L tank.

Off I went to the pharmacy and found a Magnesium+Calcium product (produced from a "dolomite sand from Norway...). It comes in the forms of pills, each of which contains 100mg of Calcium and 60mg of Magnesium. As I didn't want to raise the KH, I didn't want to go the Calcium Carbonate (CaCO3) route. 

So, according to my calculations, 15 of these tablets will raise my GH by 1.05 (200l aquarium)? This based on 1 GH being 7.14mg/l of Calcium? 

Therefore if I add 30 tablets, that will raise the GH by 2.1 and will add 9mg/l of Magnesium. 

Could someone please double check my calculations and I'd also like to know if that level of Magnesium in the aquarium is OK? 

Many thanks!


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## nino (Oct 2, 2004)

Laith,
You said you use the Dolomite Mg + Ca mixture tablets right? Did you read the ingredient? AFAIK, most of those pills contain dolomite grains and will in fact raise KH as well. 

I would just use Magnesium Sulfate to raise Mg level. For Ca, maybe others can give their opinion. I'm not sure how safe Calcium chloride is for planted tank if you don't want to use CaCO3.


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## Laith (Sep 4, 2004)

hhhmmmm... what're dolomite grains? they contain a carbonate of some type and therefore raise the KH?

The ingredients actually say (I'm trying to translate from the French) "Dolomite, lactose, corn starch".

Besides the risk of KH increase, how about the lactose and corn starch? (Stupid me I didn't see those items on the list when I bought the bottle!








)


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## nino (Oct 2, 2004)

Well, honestly, I have no idea on the effect of lactose and corn starch in aquarium. I'm more worried if those ingredient build up overtime after rounds of dosings.


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## Laith (Sep 4, 2004)

oops, did some more research and found out that dolomite is actually Calcium Magnesium Carbonate, or CaMg(CO3)2.

So you're right, it will raise my KH as well...


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## nino (Oct 2, 2004)

If you're persistence on keeping your KH level, try to search or post the effect of dosing Calcium Chloride on plants and fish. I read quite a few articles about people dosing it but I've never tried it myself. So if it works, then you can just use Mg2SO4 and CaCl to increase GH.


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## bobo31 (May 8, 2004)

3/8 teaspoon of Kent Turbo Calcium (Calcium Chloride) and 3/4 teaspoon of Epsom Salt raise the GH of my 30 gallon by 1.5

This dosage also has a 4:1 ratio.

I dose this once a week after every water change to maintain a GH of 3-4.

So if you double my dosage you should have a GH pretty close to 4. I would knock a 1/8tsp off the calcium and 1/4tsp off the Epsom Salt and see what you come up with. Since your tank is closer to 50 gallons and not 60.

HTH,
Robert.


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## Laith (Sep 4, 2004)

Ok, went out and bought some CaCl (Calcium Chloride) and MgSO4 (Magnesium Sulfate). The stuff I bought was not the best to use for this and I tried to test it in a bucket and the stuff would take like 10 years to dissolve







!

Will test the quantities suggested in tsp. Just a dumb question: when measuring a tsp or tbsp, we're talking about a level measurement right (as opposed to heaping)?


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## bobo31 (May 8, 2004)

I use level teaspoons.

Robert.


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## Laith (Sep 4, 2004)

ok, many thanks!


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## Roger Miller (Jun 19, 2004)

Both magnesium sulfate and calcium chloride should dissolve quickly. If you mix calcium chloride in a high concentration with water that has much KH in it then you will get a white precipitate of calcium carbonate. The calcium carbonate probably will not redissolve.


Roger Miller


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## Laith (Sep 4, 2004)

Roger, yes I agree. I wasn't too clear in my message. I was talking about the dolomite stuff I had originally bought: I put four tablets in a bucket and the next day they were still sitting there, almost untouched...









bobo31, how do you calculate a 4:1 ratio with 3/8 tsp of CaCl and 3/4 tsp MgSO4? Isn't the ratio supposed to be 4 parts Ca to 1 part Mg? Unless 1tsp MgSO4 has less Mg than the amount of Ca in 1tsp of CaCl?


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## bobo31 (May 8, 2004)

1/2 tsp of magnesium sulfate in 5 gallon will give you 14 ppm mg. 

About a 1/4 teaspoon of Kent’s Turbo-Calcium will increase the calcium in 5 gallons of purified water by 30 ppm. 

These together will give you a GH of 6


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## Laith (Sep 4, 2004)

Ok, Let me know if this makes sense...

Target Mg in the tank is 8mg/l, target Ca in tank is 24mg/l (3:1 ratio). Aquarium volume is 195 liters less 10% for substrate etc gives a volume of let's say 175 liters.

8mg/l of Mg is 1.4g in 175l. 10% of MgSO4 is Mg, therefore to get 1.4g of Mg you need 14g of MgSO4. At 1.35g per 1/4 tsp, that makes just over 2 1/2 tsps.

24mg/l of Ca is 4.2g in 175l. 36% of CaCl2 is Ca, therefore to get 4.2g of Ca you need 11.7g of CaCl2. At 1.6g per 1/4 tsp (KCl is 1.5 and CaCl2 is slightly denser), that makes 1.83 tsps.

1. Does this sound ok?
2. I'm confused about whether its 7.14 ppm or 17.8ppm that equals 1 GH?? Therefore the amounts above, 32ppm (24ppm + 8ppm) is going to increase GH by either 4.5 GH or by 1.8 GH?

Many thanks to all for bearing with me on this one!

Regards,

Laith


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## bobo31 (May 8, 2004)

My last post was just some number that I was given by someone on this board a while ago. Can't remeber who. I was asking the same sort of questions as you and was given the previous numbers. I really don't know much more than that. I follow these numbers and I have very good growth and no algae problems or any other problems. These numbers keep my GH between 3-4. My tap water GH is 1-2. Hopefully someone else can help you with your other questions. I was just letting you know what I do. Sorry I can't help more.

Robert.


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## Laith (Sep 4, 2004)

No problem Robert. Thanks for all your input up to now!

Can anyone else just verify that I've done the above calculations correctly?

Thanks.

Laith


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