my water is acid and gh/kh low

pH, GH and KH are inter-related. It's not too complicated changing pH--but you have to be sure of what you're doing. It's easier to raise than lower pH anyway. Personally, I wouldn't use those pH up and pH down products, they aren't permanent, and you don't even know what chemicals are in there that might have side effects.

A quick search on google came up with this:

Ways to raise the pH

· Aerate the water, driving off the carbon dioxide (CO2)
· Filter over coral or limestone
· Add rocks containing limestone to the tank or use a coral sand substrate
· Use a commercial alkaline buffer

Ways to increase kH:

· Adding sodium bicarbonate (baking soda). One teaspoon of baking soda added to 50 liters of water can raise the kH of the water by approx 4 OdH without a major affect on pH.
· Adding an air stone to increase surface turbulence driving off carbon dioxide (CO2)
· Adding commercially available products to increase buffering capacity

Ways to increase gH

 Adding limestone to the aquarium (this will also increase kH which in turn will increase pH)
 Adding calcium carbonate will raise gH and kH
Ways to reduce gH

Have you double checked your pH? Maybe you test kit is a little off.

Excel isn't going to mess with your readings. Many people here have less hardness than you and do fine. Some watch pH drop off the chart after adding CO2 and see no adverse effect on livestock, their success stems from pH stability. Keep in mind that many species we keep are found in very soft waters where pH is close to 4 or 5. It's a CO2 overdose or constant pH swings that will kill fish. If you're uncomfortable with your hardness, raise KH with a few pinches of baking soda per 5gl change water (be sure to set a measurement for yourself so as to be consistent with every change) and add a teaspoon or so of cheap GH booster consisting of a calcium and magnesium solution to bring the GH up a bit. Stay away from anything sold at big box pet stores or anything called pH Up or alkalinity buffer, it's most likely an over priced bottle of bicarb (baking soda) or even something inferior that has you going out to buy more early in the game, I used to wonder why my pH fluctuated while I used that junk, it's a losing battle. You can also raise GH with calcium carbonate and epsom salt for magnesium, a bit more effort, but probably cheaper in the long run than a store bought solution, and possibly superior depending on what solution you wind up with.

Good idea forgetting about the pH, especially when you're dealing with tap water from a treatment plant, they like to add stuff that plays games with pH. Keep in mind that this stuff precipitates out of the water over a 24-48 hour period of time. So, many who leave a bucket of tap water out over night will find that the initial pH has shifted up or down, usually down from what I read and in my own experience. Mine comes out at 8 and settles around 7.2 within 24 hours in a bucket. I used to worry about adding that to my tank right off since the tanks level at 7-7.2 without CO2 injection, then I found out it's just soda ash from the treatment plant, and probably aeration/O2 saturation, the fish don't care about it, the hardness is still the same, so adding the 8.0 water right off hasn't done any harm in over a year. If the pH adjuster manufacturers explained any of this they wouldn't make any money.

I'd either choose coral or buffering with baking soda and Ca/MG, not both. The downside of coral is that you can't totally control what it leaches, and it's usually seen in african cichlid tanks where the intention is to shoot hardness as high as it will go. Adding your own BS, Ca, an MG allows you to keep control of softer parameters which can be ideal for a lot of popular plants and fish species. the downside is that you have to take a few minutes out of change time to add them, and test the levels until you figure out how much the water will change from what you add.