Questions for chemists - esp. fishless cycling advice

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FastFish

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So I am fishless cycling my 29g, I think I've forgotten some of the principles though. I started of with 5/6 ppm NH3, a couple weeks later I added an extra 2ppm to feed the nitrosomonas sp., anyway now its about halfway cycled:

ammonia: 1ppm
nitrites: 15? ppm, off the scale
nitrates: 50-60ppm

Firstly, is the nitrite spike too big, will it stunt the nitrobacter and keep the tank from being cycled? Is a partial water change called for? Should I add more ammonia to feed the ammonia-eating bacteria? And when/if the cycle is finished, I do complete water change, right? I'm worrying that getting rid of all the water will screw my bacteria and uncycle the tank.

Then, when/if cycled, I expect to spend up to a week adding/arranging plants and aquascaping, before adding fish, for convenience and to avoid fish stress... should I feed the nitrosomonas ammonia to keep them alive? How much?

Next, I am just starting to set up a much larger 55g, I can't use the media from the 29g since its a biowheel and the 55g is going to use an eheim canister, is there any way I can speed up the cycle now that I have bacteria colonies, maybe using some of the gravel or water from the 29g? And yes I know about bio-spira and its off the market right now.

Finally, I'm worrying about my tap water , its about ph 7.1 and 130ppm GH, 80pm KH (or other way around? sorry); its not the hardness by itself that worries me, since its technically "medium-soft", but in the tank the pH has already gone up to 7.6 or so becuase of the gravel. The main thing is, I will be using CO2 injection on the 55g, which should lower the pH significantly, but what about the 29g? At this rate it will soon be fit for Rift Lake fishes, w/out CO2, what is the best thing I can do to bring it down to a range close to that of the CO2-injected 55g, maybe using 50% distilled or rainwater additive?

Thanks, -Fastfish
 

anonapersona

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Mar 7, 2003
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Not a chemist but I'll try

First, I suggest taking some tap water and measuring the pH straight out of the tap, then let it age a day or two and see what the pH is then. If this is a pH of 7.1 rising to 7.6 after the CO2 gasses off, sounds reasonable to me, I don't think that means that the gravel is a problem. That is a normal rise, I'd be happy with that water! (My water comes out of the tap at 7.6 rises to 8.1 and get to 7.1 with CO2)

Second, if you are going to be adding plants in the 55 gallon, you can do that and skip most of the time spent on trying to establish a cycle. It is best to get the CO2 going, and the lights, and add the plants, then let the plants get settled in, growing their roots back and so on, shedding any emerse grown leaves. After several, 2 or 3, weeks start adding fish -- algae eaters-- but don't feed them. Slowly after another week or 2, add more fish and start feeding lightly. The plants will be hungry for ammonia, and when the fish are added they produce ammonia which the hungry plants will suck up. You hardly even need a filter but for safety you want one. If you are worried, you can swish the filter cartridge from the 29 into the 55 near the filter inlet right before you add fish to the 55, that will get a head start on bacteria in the new canister.

Now, the 29 has a biowheel? And you will be planting it? Do some reasearch on this, the biowheel will reduce the CO2 in the tank below the level that the fish and bacteria produce. You can run the filter without the wheel and it does just fine. Consider that.

Now as for the ammonia and so on in the 29 now. Don't worry about water changes until you are ready for fish. The nitrite processing bacteria don't like ammonia so they have a hard time getting started until the ammonia is pretty low. You should be adding small doses of ammonia daily now, about half the amount you started with. Eventually, you will be able to add the ammonia and see it drop to zero in 24 hours. Then the nitrite processing abcteria will kick in and start building up to tackle the nitrite, but they are slower and so it may take twice as long for that to pass as the ammonia part has taken.
 

happychem

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Originally posted by anonapersona
First, I suggest taking some tap water and measuring the pH straight out of the tap, then let it age a day or two and see what the pH is then. If this is a pH of 7.1 rising to 7.6 after the CO2 gasses off, sounds reasonable to me, I don't think that means that the gravel is a problem.
That sounds likely to me. But then, what's up with your gravel that you suspact it?
 

daveedka

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I'm no chemist either, but this might help
anonapersona hit it all on the head pretty well by my view, I wouldn't worry about the gravel or the PH too much, I dream of water with your readings ( not perfect of course but much better than I deal with) You seem to have enough buffer to not worry about crashes as long as you do your maintenance, and as long as the PH is steady you can acclimate most fish easily and they'll be happy. The tap water tests suggested are important. My tap water comes out at a perfect 7.0 and the next day it is about 7.6 as well. My Kh is 1 and my GH 11 so I add a little baking soda in my prep tank and the water gets to 7.8 by the time my KH is 4 ppm. My fish are all quite happy with a rock solid 7.8 and with the KH at 4 I don't see a drop in PH through the week.

It takes very little ammonia to keep the bacteria fed, This isn't a scientific answer, but once I saw the ammonia level drop in my 115 fishless cycle, I added a tablespoon every day, and everything worked out well. one tablespoon didn't create a testable level but did maintain the cylce in process. I could see my nitrites climb for the first few days I did this then everything settled and the nitrites started dropping Essentially once the population explosion of bacteria occurs, it doesn't take much to maintain it. A good example is the fact that ideally you never see readable levels of ammonia in your tank once it's up and running well, but the bacteria stil get enough from the fish to thrive.
I hope this helps despite the fact that it may not be exactly what you were after.
Dave
 

RTR

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I agree w/anonoapersona's dignosis of the rising pH - I have similar effects in my water, to slightly higher pH. Fish don't "read" pH, they read TDS (total dissolved solids - i.e., osmotic effects, not the pH). For breeding certain soft-water fish (Rams, Discus, some blackwater Tetras and Rasboras) you may need to read and control GH - as high TDS, high calcium and magnesium water can have a bad effect on the egg membranes of this sort of fish. The adults rarely notice or care. So if you plan to breed similar blackwater fish you may need water mods in breeding setups.

If you are maintaining but not breeding, don't do water mods just because many references cite the pH of native waters - it is very rarely necessary to match native water to keep fish. Stability of water parameters and cleanliness of the water are far, far more important to the health and long life of the fish.
 

JSchmidt

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Also, when fishless cycling, dosing with ammonia shouldn't be an occasional or haphazard thing. You should add more ammonia anytime the tank's concentration drops below your target (e.g., 5 ppm). If you don't, the first stage nitrifiers (the ammonia eaters) won't establish themselves significantly.

Some people drop their target concentration of ammonia dosing to half (e.g., 2.5 ppm) once nitrites start to spike. You can do that, but it isn't necessary (I don't drop the level of ammonia; I dose the same throughout the cycle). It is necessary, though, that you keep feeding the bacteria. Your tank is cycled when, within 24 hours, you can go from a full dosing (e.g., to 5 ppm) to zero ammonia and zero nitrites. Until then, you're not done.

Figuring out the chemistry issues is a good thing to do while you're cycling. I agree that getting measurements on a sample of aged tap water is a start. Report back to us with that, and we can help more.

HTH,
Jim
 

FastFish

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Wow, thanks for all this help, I think I understand.

So since about a week ago, I've been adding ammonia to the 5ppm point daily, now it can go from 5ppm to 0.5ppm in 24hours, I'm almost there!

So, if ammonia->nitrites happens in 24hrs, then nitrites->nitrates is presumably functioning enough to be considered "cycled"? This is fortunate, because my nitrites are orders of magnitude off the scale right now (which tops at 10ppm, btw).

Plants and fish will arrive next weekend, if everything goes well.
 

RTR

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The presence of a funtional colony of the ammonia-oxidizer bacteria unfortunately says nothing about the colony size or competence of the nitrite-oxidizer bacteria, only that there is an energy source (the nitrite) being produced that they can use.
 
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