# "Best" way to control water hardness/ph



## Jonney_boy (Apr 28, 2010)

I have a 100gal planted tank right now and am about ready to add co2 to the setup. The tank has been running for about a week (after being moved) and all the fishes seem to have settled down nicely . Tank currently has ADA substrate and a very minimal plant load. More plants to be planted as soon as the lights come in and co2 is setup.

current lighting is two 27 cfl's + 150w metal halaide

The tank is stocked with a bunch of kirbs and discus. This is the first time i'm keeping discus.


Now the question is what targets (co2 and ph) I should be shooting for and how to manage the levels.

The tank is currently at 6.4 PH, with 0 kh and basically 0 gh. What has me worried is the following

1) With discus, i'm running VERY high temps (about 84 deg F). I am concerned about the lack of oxygen in the tank. Anything I do to increase oxygen will result in me "blowing out" the co2 from the water. 

2) Adding coral will raise the gh/kh... but it will "drop" suddenly with water changes, would this not be really bad for the fish? I've also considered adding barr's GH booster but would have to "eye ball" the amount to add in as I don't know how much water I have really changed.

3) I will NOT be able to run a PH controller to shut down the co2 at night as the co2 tank is shared with another fish tank. will this pose a problem with discus? (in my 75 gal, I get a 0.2 ph drop at night, but this is a low light tank).

4) Any other concerns?


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## neven (May 15, 2010)

how much water do you plan to take out? even eye balling roughly the gh booster by figuring out the % water changes you've done will be the safest most stable method. After all, if you are off a little bit, you have the rest of your water coloumn to minimize the hardness swing


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## darb (Apr 21, 2010)

Jonney_boy said:


> The tank is currently at 6.4 PH, with 0 kh and basically 0 gh. What has me worried is the following


Vancouver tap water is not conducive to long term aquatic life, essentially a commercial GH and KH booster are your safest bets.



Jonney_boy said:


> 1) With discus, i'm running VERY high temps (about 84 deg F). I am concerned about the lack of oxygen in the tank. Anything I do to increase oxygen will result in me "blowing out" the co2 from the water.


84 really isn't all that high, as you probably already know the higher the temp the less potential O2 that the water can hold as well TDS decrease the potential O2 capacity. There are O2 test kits on the market for $20, I believe.



Jonney_boy said:


> 2) Adding coral will raise the gh/kh... but it will "drop" suddenly with water changes, would this not be really bad for the fish? I've also considered adding barr's GH booster but would have to "eye ball" the amount to add in as I don't know how much water I have really changed.


Yes, PH swings are bad for fish, ideally the new water should match the stable tank water. Look at treating your water before you introduce it to the tank. I use pure calcium carbonate in my water change water.

You should have a pretty good idea how much water you have taken out, either in buckets or percentage of your tank, minus an estimate of the volume of substrate and other items.



Jonney_boy said:


> 3) I will NOT be able to run a PH controller to shut down the co2 at night as the co2 tank is shared with another fish tank. will this pose a problem with discus? (in my 75 gal, I get a 0.2 ph drop at night, but this is a low light tank).


Probably better for your fish anyways since it will aviod the daily PH change, as long as your O2 stays high enough.


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## Jonney_boy (Apr 28, 2010)

yes I can eye-ball the water change, I'm using a python currently to do the water change and will take out 30-40% of the tank every other day or so.

As for an O2 test kit,.. never even knew there was such a thing..... time to go shopping 

so it "seems" that the best solution is to use a gh/kh booster 

As for the co2, is there a particular target I should be aiming for? I was told that discus where sensitive to co2 (and a lack of O2) and thus should keep the CO2 to a minimal. I know I try to push 30ppm in my 75 gal tank and still get a bit of bba that needs to be cleaned out every few weeks.


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## Rastapus (Apr 21, 2010)

Jonney_boy said:


> yes I can eye-ball the water change, I'm using a python currently to do the water change and will take out 30-40% of the tank every other day or so.
> 
> As for an O2 test kit,.. never even knew there was such a thing..... time to go shopping
> 
> ...


Yes! GH and KH boosters are your best bet in maintaining levels and pH.


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