Cycling my 55gal.. how basic is too basic?

[shallowbreath]

I've been cycling my 55 gallon freshwater tank for a few weeks. I have my fiancee's 10gal which has been the source for most of my bacteria (I know its frowned upon but I did use some off the shelf inoculate because I was concerned I did not use enough bacteria as she just tossed her sponge filter ) and so far things are going according to plan; the bacteria can eat about 3ppm ammonia in 24 hours and my nitrites are showing up at 4-5ppm. One thing I'm concerned about is my pH. It is blue off the scale, where my test tops out at 7.8, and I am using 30 wt% ammonium hydroxide obtained from my professor to feed it. My KH is 4 degrees (baking soda) and GH was inconclusive (probably zero). I have been chasing the ammonia doses with some light doses of API pH Down but I am worried that my water will become caustic at this rate. Should I add more pH Down until I can see the pH on my scale, and what can I do to increase GH without screwing anything up?

Filter: Fluval 304, > sponge / prefilter / empty / biomax >
Temp: 84F
KH:4
GH:?
Nitrite: 5ppm
NH3: 1ppm (drops to 0 overnight pretty much)
pH: 7.8+
nitrAte: 5ppm last I checked

 

[epond83]

Well the first thing is to test your tap water and see what it is. I think the ammonium hydroxide gives of -OH ions which will make your water more akiline. Most people just use pure uncented ammonia for cycling. You may want to switch to that. If your tap water lower then after a few water changes it will come back down. Been awhile since chemistry so i could be wrong but that is my guess.

With that being said constante pH is better then a certain number, but if you are adding something that is raising it i would stop. Also most a lot of people don't like using pH up or down, better to just let it be stable then messing with it.

 

[unwritten law]

I think that ammonia hydroxide is cause the pH raise. I wouldn't worry cause once the cycle is done you'll do a HUGE w/c and the new water should have a lower pH. Another way to lower pH is to add drift wood.. But its a gradual affect.

 

[homebunnyj]

Yeah, you don't have fish in there so don't sweat the pH. Just grow your bacteria, and when the tank is cycled, as was said above, the big water change just before you add the fish will take care of all that. And as was also said above, you can test your tap water now to determine what its pH is. You probably have absolutely nothing to worry about in that area.

 

[epond83]

Like the others are saying you are fine because there are no fish. I'm not sure how senitive the bacteria are to pH but i know it is best to grow your bacteria in the same condtions as the final set up. This shouldn't be a problem, but the question is how high is your pH? I think the pH of what you are adding can be close to 11 so you might not have the best condions for the bacteria.

But you are probably going to be ok, just make sure to do that really large water change and see if you are registering on your pH test.

 

[shallowbreath]

Thanks for the replies! Some notes:
the ammonium hydroxide i'm using is just to feed my nitrosomonas; its just much purer than commercial grade ammonia.
wiki says that nitrobacter works best at 7.8 ish, but from the responses it seems that it can survive much higher than that, and my fish won't have to!

I am still wondering how I can raise my GH, since it will be very useful to have nicely buffered tank water for my fish when I'm done cycling.

Thanks!

 

[epond83]

baking soda i beleve can help buffer your water but as long as normal tank operations don't cause large fast pH swings it will be fine.