eaglescout316

I just got a couple more API test kits (i already have the master kit, but they make so many more!) and found out that my carbonate hardness is 5 (or 89.5 PPM), and my general hardness is 9 (or 161.1 ppm).

I feel that this seems excessive, since the test recommmends 3-6 being the range for each. The major thing i've learned from searching the internet is that it's really hard to learn about these parameters. I understand carbonate hardness is related to water buffering to maintain pH, but general hardness eludes me. My questions are 1) what does general hardness mean to my aquarium and 2) is lowering it a bad idea just like lowering pH?

Thanks in advance

sirdarksol

The effects of general hardness on the aquarium are related to osmosis. A fish' cell membranes flush water in either direction to maintain a balanced water:mineral ratio. Each type of fish has a different preferred hardness. For example, the Amazonian fish like very soft water, while the African cichlids prefer harder water. If the water is too far from a fish' preferred hardness, it begins suffering from osmotic stress, as the water:mineral ratio in the cells is not kept at an ideal level for it.
Most fish don't have much of a problem with this. I have my tetras in extremely hard water, and they are doing very well (colorful, active). If stacked on top of other problems (incorrect temperature, excessive wastes), osmotic stress can mean the difference between health and illness.

Lowering hardness is not as bad as lowering pH, but it is incredibly difficult to do. Generally, the only way I know of to do it is to mix pure water (RO, distilled, or rain) with tap water when doing water changes. There are, as far as I know, no chemicals that you can add to a tank to remove minerals.

pepetj

9 dGH and 6dKH are perfectly fine for most fishies we keep. If you want to check easily if you should or not tamper with your general hardness, do this simple screeneng REDOX potential test: take some water out of your tank in a plastic disposable container, add some Methylene Blue and see if the dark blue color fades, even if just a bit. If it does, your REDOX is likely to be OK and you could consider your water safe for your fish health.

Pepe
Santo Domingo

Jess

I have to admit, I'm also still confused with the GH and KH. Mine is very low. My water pH is around 6.4. And seems stable. Is this something to be concerned about?

sirdarksol

It shouldn't be.
There are only a few times that you really need to worry about any kind of water hardness:
If you have fish with very specific requirements, such as African cichlids. These are fish that will actually get ill if they don't have the right hardness.
If you're trying to breed certain softwater fish. Most tetras won't breed in hard water. It's difficult enough to get them to breed, anyway, but hard water makes it nearly impossible.
If your pH is not stable. If it drops precipitously between water changes, this means your hardness is too low (and probably that your tank is overstocked), and is not buffering the water enough.

If you've got a stable pH, and don't have African cichlids (which probably wouldn't like living in 6.4 pH), you shouldn't ever have to worry about hardness.
Frankly, I wish I had water like yours. It's an easy enough task to raise pH and hardness, but it's a pain to lower either.

Jess

Ok I'll stop worrying. It seems pH is stable with changes. You're correct I'm highly stocked but moved out 2 discus to another tank to lighten aggression.

I've been pleased with our water. Who ever is taking care of it is doing a good job. I occasionally test right out of the tap to see what I'm working with and its always the same.

Thanks for you response. : )

sirdarksol

I wasn't talking about your tank when I was talking about being overstocked. I was referring to folks who have pH drops, which would indicate too much waste degrading between water changes.

Jess

: ) Not a problem.

rrrswayn

Hi guys, totally new to the game and might sound really silly but in order to increase the gh of your tank, do you add more or less conditioner?? my hardness is currently testing at 210 ppm, but i was told at the fish shop the optimum range is between 250-300ppm.... wondering if this is true and if so how would i go about getting my levels in that range?? thank you in advance for any help and advice, where would all the newbies be without you all!!!

pepetj

This is an information I consider to be totally conditioned to the species you aim keeping. As for most common tropical fish I would say not really! Your readings are fine. Just not ideal for Discus -who might/must need softer, or most African Cichlids -who might/must need harder.

I suggest you do some reading around -I am still doing so- the subject of hardness/alkalinity is not that easy to grasp but it's understandable if we put our head into it.

Pepe
Santo Domingo