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Discussion Starter · #1 ·
I have a ten gallon planted tank with 3 guppies (and a snail that hitchhiked). I just added the guppies 2 days ago. Back when I was still cycling I added an extra bag of gravel and the Ph shot up to 8.2. Because my tap water has 7.6 Ph it was slowly comming down with water changes. However, I just tested it again and got this:
Ammonia- 0
Nitrite- 0
Nitrate- 10
Ph- 8.2

What made it come back up?? The only thing different lately is I added fish... But that shouldn't do anything to Ph. I know that livebearers like more basic water but 8.2 seems a little high.

On another note, I just added 3 guppies and my biological filter and plants are handling it with flying colors. Is it safe to add another 3 guppies? If not when do I know when it is safe to add more?

Thanks in advance :-D
 

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What kind of rocks did you add? Calcareous rocks will raise your pH, this would be things like crushed coral, aragonite, or similar. They will continue to 'dissolve' minerals forever until gone.

However, a pH of 8.2 is nothing to worry about with these fish. A perfectly neutral 7.0 is actually extremely abnormal in nature. The important thing is stability. You don't want the pH swinging by a large amount. pH will often change a little throughout the day, but not by a large amount in a healthy system. Be sure you test at the same time every day because of that.

As for adding fish, I would wait at least 2 weeks, if not 4 weeks, before new additions. This is assuming the new fish were not quarantined as most people don't.

Even if quarantined, I'd wait 1 week minimum. You want to give the tank time to adjust and to ensure no ammonia/nitrite is forming.
 

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....

As for adding fish, I would wait at least 2 weeks, if not 4 weeks, before new additions. This is assuming the new fish were not quarantined as most people don't.

Even if quarantined, I'd wait 1 week minimum. You want to give the tank time to adjust and to ensure no ammonia/nitrite is forming.
Ditto.

Jeff.
 

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Discussion Starter · #4 ·
What kind of rocks did you add? Calcareous rocks will raise your pH, this would be things like crushed coral, aragonite, or similar. They will continue to 'dissolve' minerals forever until gone.

However, a pH of 8.2 is nothing to worry about with these fish. A perfectly neutral 7.0 is actually extremely abnormal in nature. The important thing is stability. You don't want the pH swinging by a large amount. pH will often change a little throughout the day, but not by a large amount in a healthy system. Be sure you test at the same time every day because of that.

As for adding fish, I would wait at least 2 weeks, if not 4 weeks, before new additions. This is assuming the new fish were not quarantined as most people don't.

Even if quarantined, I'd wait 1 week minimum. You want to give the tank time to adjust and to ensure no ammonia/nitrite is forming.
It was just normal aquarium gravel... Now that I think about it I put in a single rock to tie my java fern to as well. But I don't think that could cause a .4 Ph jump...

Ok, I'll wait longer to add more fish,

Thanks for the feedback
 

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I would re-test your tap water. Assuming you tested it yourself, you may not have out-gassed the CO2, and this will give an incorrect (and lower) reading. To out-gas the CO2, let a glass of tap water sit for 24 hours, or place some in a jar and shake it very briskly for a few minutes. Then test. You may find the tap is closer to 8.2 in fact.

Regardless of that, as someone mentioned the livebearers will be fine in harder water with a higher pH. Soft water fish would be a very different story.

Byron.
 

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Discussion Starter · #7 · (Edited)
I would re-test your tap water. Assuming you tested it yourself, you may not have out-gassed the CO2, and this will give an incorrect (and lower) reading. To out-gas the CO2, let a glass of tap water sit for 24 hours, or place some in a jar and shake it very briskly for a few minutes. Then test. You may find the tap is closer to 8.2 in fact.

Regardless of that, as someone mentioned the livebearers will be fine in harder water with a higher pH. Soft water fish would be a very different story.

Byron.
Ok, thats probally a good idea. Ok, I will.

Edit: I just realized that as well as adding fish I have also kept the air pump much longer every day.. Your post on Co2 gassing out reminded me of that. Thats probally why my Ph went back up.
 

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I have a ten gallon planted tank with 3 guppies (and a snail that hitchhiked). I just added the guppies 2 days ago. Back when I was still cycling I added an extra bag of gravel and the Ph shot up to 8.2. Because my tap water has 7.6 Ph it was slowly comming down with water changes. However, I just tested it again and got this:
Ammonia- 0
Nitrite- 0
Nitrate- 10
Ph- 8.2

What made it come back up?? The only thing different lately is I added fish... But that shouldn't do anything to Ph. I know that livebearers like more basic water but 8.2 seems a little high.

On another note, I just added 3 guppies and my biological filter and plants are handling it with flying colors. Is it safe to add another 3 guppies? If not when do I know when it is safe to add more?

Thanks in advance :-D

Simple.. the plants are reducing carbon dioxide which raises pH.

Very common in planted tanks. In fact with my non filtered, no circulation tanks those values are normal and expected.

IMHO it is hardly dangerous to the fish to have a low co2 environment.


my .02
 

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you have this revers, ph lowers not raises :p

Actually it works both ways.

raising pH lowers co2

lowering co2 raises pH.

With planted tank I emphasize the later. As the plants lower the co2 the pH rises. Just as adding co2 lower pH.

for the really nerdy:

CO2 (atmosphere) + H2O <->H2CO3
H2CO3 <->HCO3- + H+
HCO3- <->→ CO3-- + H+
 

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if you notice some plants will use CaCO2 as a carbon source which has a direct impact on your kh which in turn effects your ph. the more caco2 the plants use the more your kh will lower in a result of a lowering ph. the naturally occurring co2 in a tank is minimal and the built up stores are used within gthe first few hrs of light on. the effect of naturally occurring co2 on ph in a aquarium is minimal. about the same as the plants using the caco2.

*shrug*
 

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if you notice some plants will use CaCO2 as a carbon source which has a direct impact on your kh which in turn effects your ph. the more caco2 the plants use the more your kh will lower in a result of a lowering ph. the naturally occurring co2 in a tank is minimal and the built up stores are used within gthe first few hrs of light on. the effect of naturally occurring co2 on ph in a aquarium is minimal. about the same as the plants using the caco2.

*shrug*

Agree

except that with a heavy fish load there is significant co2 in the water.

And I remember seeing one analysis by dr randy holmes farley that plants actually return carbonate to the system as they reduce nitrates to plant tissue. And in the same amount the aerobic bacterial used up the carbonate (alk).

From the same article the anaerobic /anoxic bacterial also add carbonate consuming nitrates.

My observation is that even with peat moss in the substrate I have a pH of 8.4-8.8 (api high range test kit) in my tanks.

my .02
 
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