Sue's Fishless Cycle

Day 7  17 March

Ammonia 0.5
Nitrite 0
Nitrate between 5 and 10



Possible explanations for yesterday's odd readings.

I hadn't done a nitrate test for ages. Did I fail to shake bottle 2 enough when I did the baseline test, and therefore got a reading lower than it should have been? Then when I tested yesterday, having been shaken on day 1 and day 6, the reagents were more thoroughly mixed and gave a truer reading.

I am working with a much lower than usual dose of ammonia as a single betta in 25 litres will only make a smal amount of ammonia. When dosing to 4 ppm, it is very difficult to tell the difference between 4 and 3ppm (the colours at this level are 2, 4 and 8ppm) so a small decrease in ammonia isn't noticeable. But at low levels the colours are 0.25, 0.5, 1.0ppm so a small decrease is more obvious. Am I just seeing evaporation of ammonia?

Could you test by the (simulated daylight) light of one of your tanks then it's always a constant? You could test a known zero for NH₃ by the same light to get a benchmark. It's perhaps not so much the quality of the light as the consistency of it that's important?

Just a thought.

It looks like the kitchen lights were the problem. I added the ammonia during the afternoon and the first few tests were squeezed in when there was just enough daylight to see by. From now on, I'll test straight after breakfast and by the time I need to do 12 hour tests, the hour will have gone on so it'll be light after dinner.

There's a really good article on here that mentions this very problem!  Have a look it may help you 

If you have bought the API liquid testers, there are two quirks to be aware of.
Firstly, the ammonia test shows yellow for zero ammonia, then turns green as the ammonia level increases. Fluorescent lights, including energy saving bulbs, emit a greenish tinge to the light, and this can make the colour in the test tube look greener than it really is. Whenever practical, it is better to read the test in natural daylight or under an old fashioned light bulb.

Actually my API ammonia test NEVER really looks the full yellow colour. It's always a slightly off yellowy colour no matter what colour and even on my tapwater. I have no idea why! It's obviously at 0 though as it's not green enough to be 0.25ppm

What you read time and time again is that it is very difficult to get the pure yellow which represents zero, and that fluorescent lights, including energy saving bulbs, make the liquid look greener than it really, ie it makes the ammonia level look higher than it really is.
I have never had any problems seeing the pure yellow in all lighting conditions.

I have just done some research. I've done another ammonia test now that daylight is so dim we've had to draw the curtains. I've looked at the colour under 4 different lights. Remember that at lunchtime in full daylight it was 1.0 - or to be precise, a tiny bit yellower than 1.0 but far greener than 0.5, so I called it 1.0.

Tonight's results:
Fluorescent tube - 0.5
Energy saving bulbs - 0.5
Incandescent bulb - 1.0 (same as daylight)
Halogen bulb - 1.0 (same as daylight) [that's the kind of halogen bulb that's the same shape as an incandescent bulb]

My ammonia isn't dropping at all, it just looks like it when I read the test in the kitchen in the evening. I'm going to change to doing the 24 hour testing after breakfast. The hour goes on in 2 weeks, which means it will be daylight later in the evening. This will make 12 hour testing more reliable when I finally get to that stage.



Can anyone explain why my flourescent lights of both types make the liquid look YELLOWER than it really is? That's the opposite of everything I've ever read 

Tonight's results:
Fluorescent tube - 0.5
Energy saving bulbs - 0.5
Incandescent bulb - 1.0 (same as daylight)
Halogen bulb - 1.0 (same as daylight) [that's the kind of halogen bulb that's the same shape as an incandescent bulb]

Can anyone explain why my fluorescent lights of both types make the liquid look YELLOWER than it really is? That's the opposite of everything I've ever read 

Although the colour temperatures of all of these bulbs is nominally similar, and by the way none of them are daylight bulbs, the actual contents of the spectra are different.  This is due to the differences in the technologies that actually produce the light.

The spectra for an incandescent bulb is defined by a bell curve.  It's a smooth continuous curve shaped like a bell! [surprise!]

However, the same spectra for a fluorescent tube is made up of a number of spikes at different frequencies; So some colours are over-represented and some colours are absent altogether; It depends on the mixture of chemicals used in the manufacture of the tube.  The curves that may be published just average all these out into a smooth curve.

My guess is that the 2700K tubes that are pretty standard household bulbs have a spike in the yellow!

Thank's for that Steve. Lesson learned, I'll use daylight from now on!

Colin - 30^oC is recommended for fishless cycling as the bacteria like it that high and grow faster. At the big water change at the end of the cycle, we turn the heater to the setting the fish need. Mine is at 30^o as well.

Chris - I'm using Kleen Off as well, but a rather old bottle so a lot of the ammonia has evaporated which is why I haven't mentioned the number of drops as I will have used more than someone with a new bottle will need.
I've chosen 1ppm as there will only be 1 betta in the tank which will need less than 4ppm-worth of ammonia, probably less than 2ppm-worth. And starting with 1ppm rather than 2 means I'll have less nitrite. Once both are dropping to zero, I'll increase the ammonia dose to 2ppm.



Day 9 19 March - 8.15am in daylight

Ammonia 1.0

Colin - 30^oC is recommended for fishless cycling as the bacteria like it that high and grow faster. At the big water change at the end of the cycle, we turn the heater to the setting the fish need. Mine is at 30^o as well.

Ah - that makes sense. I read that as aiming to keep the tank at 30^o for the fish, not just for the cycling process.

The vast majority of the bacteria live in the filter, but they do grow in the biofilm on every surface in the tank. Gravel would have some bacteria, though not enough to drastically shorten the cycle. There should be enough to start it though especially if you put it in the filter where the water first enters, as you suggest. As you can see from my attempt, it's getting the bacteria started that's the slow bit 

sue- bit dull me starting off at 4+, when i should be starting off lower. can i just wait for it to drop below 1 and then top it back to 1 and then top it up higher towards the end?

You could do a 75% water change to bring it down to around 1ppm.