Green Goddess's First Fishless Cycle (240 Ltr)

[waterdrop]

You've crossed over from the first phase (waiting for ammonia to drop) to the second phase of fishless cycling GG. The second phase is called the Nitrite Spike phase and during this phase you can actually ease back a little to 3ppm (its just sort of a guess and 3 is better than two) and also we'll have to keep an eye on that high NO2 and NO3 as we might decide we need to water-change it out. Basically its a trade off between the fact that not disturbing anything is good as it keeps things rolling but on the other hand the high buildup of nitrite and nitrate can eventually inhibit the growth of the Nitrospira (the N-Bacs or nitrite oxidizing bacteria as we sometimes call them.) So at some point (sometimes I wait until NO3 is 160ppm) you just change water down to the gravel and replace it with normal good technique and then recharge the ammonia back up to 3ppm.

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[greengoddess]

Thanks Waterdrop,

OK, I'll keep a close eye on the levels and if anything gets out of hand I'll let you know.

I will ease back on the ammonia to 3ppm the next time I need to add some. The tank water is still nice and clear at the moment with no sign of cloudiness. That reminds me... I must get round to posting a photo of the tank.

 

[waterdrop]

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[greengoddess]

Tested again today exactly 24 hours since the last test. Amm = 0, Nitrite 5, Nitrate 110. I added another dose of ammonia to take it to around 3ppm.

 

[waterdrop]

Must confess I'm curious whether a tablespoon or two of bicarb would -lower- that pH if its still way up above 9 and the other thing I'm watching is that very high nitrate number which might cause us to want to do a large water change at some point before it inhibits the N-Bac growth.

BUT, this fishless cycle has moved so quickly to the second stage that we really don't want to touch it as it seems to know what its doing so far!

~~waterdrop~~

 

[greengoddess]

Hi,

Pardon my ignorance but surely adding bicarb would raise the pH. Have I missed something really obvious?
Anyway, I have always had trouble reading the colour cart for the liquid pH test. The colour is really hard to match to anything. I tested the water today with two different sets of pH papers and both sets said the pH was between 7 and 8. I did the liquid test again and I think perhaps I have been reading the colour incorrectly. Perhaps the pH is only 7 or 8 after all. I am going to take my liquid pH kit to work tonight and test it properly in the lab to check each colour. That way I'll have an accurate answer on the pH of my tank water.

Regarding the nitrate level, I am entirely at your mercy. If you think I need to do a water change then just let me know. Having said that, doing one over the next few days will be a struggle as I'm working 12 hour night shifts. I can do one at the weekend if I need to.

Today's results:

Amm = 0
Nitrite = 4
Nitrate = 110
pH = open to debate, possibly 7.5.

 

[waterdrop]

Well that's perfect then, we'll just decide to not do any water changes while you have extra work!

Yeah, I think I was reading the baking soda link at Arm&Hammer or maybe some other bicarb ref and it was talking about how bicarb would work to pull the pH downward if it was too high (or upward like we're used to)... I didn't fully understand it and of course in your case I don't really think we'd want to "experiement" with your fishless cycle.. it was mostly just me thinking out loud.

~~waterdrop~~

 

[greengoddess]

Hi Waterdrop,

I spent a while testing out my pH kit at work last night. I can now confirm that the pH of my tank water is 7.7 - 7.8pH. I've thrown away those useless pH test papers. Even when dipped directly in bicarb they don't show the pH above 8.0 so I think they must be well out of date. Anyway, I'm glad the pH in my tank is not above 9.0 as it takes another possible problem out of the equation. Now we just need to keep an eye on the nitrate level.

Today's results:

pH 7.7 - 7.8
Amm 0.0
Nitrite 3.3
Nitrate 110

Added ammoinia to bring level back to 3ppm.

 

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[greengoddess]

Another strange result today. I checked for nitrate and it went to the usual dark purple colour within a few seconds but as I waited the required 5 minutes the colour gradually went paler to an orangey red colour. This is strange as the colour usually ranges from a pale pink to a deep purple. So, either the nitrate has inexplicably fallen to around 20 or the test kit can't cope with the high reading and has thrown a complete wobbler. I'd be interested in your opinion. Other than that, the ammonia was zero and the nitrite was 3.3.

 

[waterdrop]

Hi GG, seem to remember you using a Nutrafin kit or a combo of kit types? So don't quite know about your colors. With that high (110 repeatedly?) nitrate(NO3) you've been showing I would say you could try a large gravel-clean-water-change some weekend if you got inspired. Sometimes that brings the nitrate and nitrite levels down and stimulates the N-Bacs to grow a little faster. But its not necessarily critical and you always potentially lose a day or so with a water change during a fishless cycle because sometimes the bacteria seem to shock and do nothing apparently because of the disturbance (or it could just be that its hard to interpret the test results right after a water change, as we'd expect.)

~~waterdrop~~

 

[greengoddess]

Hi waterdrop,

Yes, I use the Nutrafin kit. I tested it again this evening and it went the same pale red colour. I also noted that it says in the instructions that a high nitrite level can affect the result of the nitrate test. I think I had better do a water change as you recommend. So, do I drain the water right down to the level of the gravel and then refill with dechlorinated water? Does the fresh water have to be at 29 degrees or can I just put cold water in and wait for the heater to do its job?

Today's results: Amm = 0.0, Nitrite 3.3, Nitrate ?

 

[waterdrop]

It should not hurt the bacteria (afaik) to do an entire refill of cold water (talking the really cold water you can get in winter I guess) and wait for the heater to warm it. In my case what I always did was use these sessions to "practice" my weekly gravel-clean-water-change procedure, knowing in coming weeks I'd have to do it with fish and would have to get it all, including the temperature, right! So I used it to figure out my temperature matching technique, figuring this would also keep the bacteria clipping along at maximum division rate if possible.

Is the max nitrite value on the Nutrafin kit a 3.3?

~~waterdrop~~

 

[greengoddess]

OK then, I may as well try to keep the temperature constant at 28 or 29 celcius when doing the water change. As you say, it's good practice for when I have fish in there anyway. I will also have to adjust the pH of the incoming water using bicarb again. Hopefully this time I'll get it to around 7.5 or 8.0 instead of through the roof like last time.

Yes, 3.3 is the maximum on my nitrite test chart. Earlier on in the cycle the nitrite was off the scale and I estimated it at around 5.0. At the moment it is a steady 3.3.

I'll do the water change tomorrow as it's the only free day I'll have for about a week. So, just to make sure I get things right... I drain the water down to the gravel, top it up with fresh dechlorinated water at 29 degrees (and pH of 7.5 - 8.0) and I assume I also add ammonia straight away to give the bacteria some food. Is that correct?

 

[waterdrop]

Yes, you've got it right GG, you do indeed go right ahead and recharge the ammonia and the bicarb right away after the water change. In my log entries in my notebook I would always say "X% H2O chg w/Prime, NH3 and Baking soda" so that when I looked to write it the previous entry would jog me if I'd forgotten something!

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