Justfrozen's Fishless Cycle Log

[JustFrozen]

my nitrate was really low again, about 15 ppm. does this mean my bacteria just arent growing?

i've completed the 90% water change.

 

[waterdrop]

Sorry guys, I clearly wasn't paying attention when I wrote that. I was thinking of the crushed coral that sometimes get used later. My understanding from some of the Hovanec interactions is that there's nearly always enough trace Ca and iron in even a small water change to satisfy the small needs of these cells. I've written that before and if I'd been paying attention, wouldn't have given the misinformation up above.

~~waterdrop~~

 

[JustFrozen]

Any chance I can get an answer about the low nitrate? I know we discussed before about that test being wildly inaccurate if not done properly, but considering I keep getting the same result, maybe my cycle just isn't progressing? Looking at my latest numbers I notice that before the 90% water change I had the low nitrate, and post water change I still had a nitrite level that appeared to be off the chart, although it wasnt that teal color after 5 minutes.

As usual I just want to course correct if I'm messing something up. What's so different about the nitrite consuming bacteria versus the ammonia consuming kind? Are they more particular to temperature or something?

 

[OldMan47]

When you test for nitrates in any of the common test kits, the second chemical that you add precipitates in the bottle while it sits on the shelf. Unless you mix at least as long as they recommend, including bumping the bottle on a table top to shake things loose, the readings can easily come out lower than it should. If you are not sure how long you have been shaking the bottle, do not estimate it, just start timing where you already are, as if it is the first second. Your results will be much more consistent that way.

 

[JustFrozen]

When you test for nitrates in any of the common test kits, the second chemical that you add precipitates in the bottle while it sits on the shelf. Unless you mix at least as long as they recommend, including bumping the bottle on a table top to shake things loose, the readings can easily come out lower than it should. If you are not sure how long you have been shaking the bottle, do not estimate it, just start timing where you already are, as if it is the first second. Your results will be much more consistent that way.

I usually bring up the computer clock and watch the time by the second, especially for nitrate since there are multiple things to time. Usually for the regular 5 min wait i use the timer on the iPhone. I found myself forgetting about it far too often with any other way,

Based on advice you've given previously, I've been shaking it vigorously for at least 50% longer than the directions say. I'd like to be optimistic and say the nitrate tests are way off, but it just doesn't look that way. I haven't been hitting it against a table though. I'll hit it around like crazy tonight

edit: done. it's definitely low. it's at 5. now i recall the same color last night, and recorded it higher

 

[waterdrop]

You are correct that nitrate(NO3) measurements are used to some extent to confirm that the nitrogen cycle is running its course and getting to the final product. You are also correct that we always need to be wary of the test itself being inherently unpredictable to a certain extent.

However, there's more! (at least in my opinion) I find nitrate(NO3) measurements to be a "slow to move" type of feedback. For instance, they often seem to not go -down- as fast as one would expect when doing muliple large water changes. Likewise, the often seem to not go -up- as fast as one would expect -after- water changes and when you feel the cycling processes are back at work. I do not pretend to have a nice solid explanation for this but a part of the guessing that is a work in progress for me has to do with some things I've read about the various "in solution" forms that nitrate compounds take having charge characteristics (we're talking an NO3- ion you realize, as a starting point) that may mean they are not always evenly distributed in the tank but may "hang" more tightly with the filter media and gravel. Even a little of this effect combined with all the other variables may make for less predictable swings in these measurements as we see them.

The other little wild card in there for nitrate(NO3) tests is that there are various thoughts about how the measurement is thrown off if there is nitrite(NO2) present in the test water. We know that NO3 tests are the most stable and predictable after the tank is mature and normal and that's the time when nitrite(NO2) is consistently found to be zero ppm. There are reports that nitrate tests are thrown off by nitrite but I've not found supporting literature for it so can't comment with confidence. In truth, I feel that we are more confident about the usefulness of NO3 results -after- fishless cycling, whereas -during- fishless cycling we happily point to them when they bolster our hopes, and ignore them when they don't.

~~waterdrop~~

 

[JustFrozen]

Is there any difference in water temperature tolerance in N-Bacs vs the A-Bacs?

 

[waterdrop]

Is there any difference in water temperature tolerance in N-Bacs vs the A-Bacs?

Interesting, wish I knew! There probably is but the only source I know of discussing this is once again Hovanec and he makes no differentiation between them. He's our source for running the growing tank warm, up in the 80's F, not in the 70's, but he's also the one who expressed concern with it getting a little too hot which was why I backed off to 84F/29C as about optimal. He's also the source for pH range of 8.0 to 8.4 as optimal and falling off above and below that. WD

 

[JustFrozen]

thanks WD your wisdom is appreciated as usual.

there's apparently a small list of things i could be doing wrong at this point. the ammonia drop went like clockwork, so any difference in nature between that and the nitrite spike phase is not only interesting, but helpful. i've got this feeling that the temperature in my tank is fluctuating, or at the very least just not optimal. it's hard to tell with the equipment i have, but i suppose there's an easy way to remedy that, aside from funds being low. 'tis the season after all

 

[waterdrop]

Looking at your log in the first post it just strikes me that pH keeps going closer to 7 than to 8 for long stretches. You obviously have KH that's on the low side. I forget, have we had any conversations about baking soda?

A cheap device for extra temp checks is simply an extra cheap glass thermometer or two and some extra log entries. I don't really think temp is as significant as pH.

Of course, you realize probably all of this is in the nature of the boring stretch of the nitrite spike. When it comes out of it it usually comes out suddenly.

~~waterdrop~~

 

[JustFrozen]

Looking at your log in the first post it just strikes me that pH keeps going closer to 7 than to 8 for long stretches. You obviously have KH that's on the low side. I forget, have we had any conversations about baking soda?

Yeah, you've brought up the baking soda thing multiple times. My tap water is 8 so I've just been doing water changes to get the pH back up. Part of that is because I still haven't remembered to buy some, and part of it is that I've not yet read anything that indicates that it is preferential over water changes for that situation (other than ease of use).

Yeah, I suppose it IS odd that my pH drops so quick. It's got to be what's going on in the nitrogen cycle though, because I'm 100% positive I have hard, alkaline tap water.

 

[OldMan47]

You are right JustFrozen, the only real advantage of bicarb is that you can chuck a bit into a tank, stir it a bit, and the pH will bounce right up for you. It is much easier than a water change but is no way a better choice. If you can control pH with a water change, that is almost always a better choice.

 

[waterdrop]

Yes, I admit to a bit of an experimental wish here. If you go back a year you could find me writing pretty long posts encouraging individuals to stick with water changes if at all possible to raise the pH during the fishless cycle, rather than use bicarb. One of my concerns back then was that even though you intend to do the 90% water change at the end, it seemed like bicarb would still leave some excess sodium in the tank and that seemed like an unknown.

Over time I've felt less sure about this tradeoff. This is all from reading threads of course, I'm certainly not running a building full of experimental tanks as we all know, lol. I just keep getting a sense that the tanks that seem to stay locked up at or close to 8 go faster than the ones fluctuating down in the mid to low 7s and I never see many feelings or hunches that sodium from the bicarb ever amounts to a concern (the assumption being of course that its use is dropped once you have fish.)

I'm very aware we've always tried to steer clear of as many artificial adjustments as possible and in fact I feel its often been me and OM47 trying to hold things that way.. I don't know, what do you think OM, I don't know why I get this longing for someone with low KH to just try baking soda adjustments from the beginning and for us to see whether that fishless cycle drags out less. Its probably just wishful thinking.

~~waterdrop~~

 

[OldMan47]

If I had that issue myself, WD, I might try it just to know for sure. I have a personal prejudice against anything that is fast acting in a fish tank and that includes the bicarb. I like to see things moving slowly or at least in small measured steps. The bicarb is almost instant in its action and can make dramatic changes in both pH and KH so I am leery of it when I have fish in a tank. It is safe to use with a cycle but is still not something I would want to get used to doing, then add in the fish.

 

[waterdrop]

Completely with you here. Have often written long posts encouraging people to only use bicarb for fishless adjustments (and only when really needed usually) but to then switch, once they have fish, first to trying to control things with water changes (like I do with my zero KH) and if that doesn't work then and only then to consider using crushed coral in mesh bags in the filter. Once you have fish, crushed coral is the way to go because of its slowness, bicarb is too fast.

~~waterdrop~~