Measurable Nitrites

Hello All.

I started a freshwater tank in summer 2011. 30 gallon Marineland, sand substrate, AquaClear 70 filter. I cycled the tank with pure ammonia. No plants as yet (that aren't plastic), but I am considering some java moss.

The tank has been stable since October. I measure for ammonia/nitrites/nitrates once per week, and do at least one 30% PWC per week (it's been trending toward two since I added the plecs - the nitrates are rising much quicker now).

Once every two weeks is my "big" clean. I pull the decorations from the more heavily decorated half of the tank (to get at the sand underneath), and clean the filter as well. This "big" clean occurred most recently this past Saturday. When taking water chemistry readings the day after the cleaning, I measured some nitrite content (~.20 ppm). I did an immediate 50% PWC and measured again (a much less blue reading, as expected).

The day after that, I measured again, and the nitrites looked a bit higher (let's call it 0.15). I did a 30% PWC. And that brings us to today. I measured again when I got home from work, and the reading was pretty negligible - maybe a hint of bluishness, but mostly the pastel green which means 0.

So why the nitrites? That's my question. I don't overfeed, and all fish are alive and accounted for. What follows is a list of things that were new this weekend:

• I introduced a Filter-Max III pre-filter sponge onto the intake of the HOB.
• I cleaned the filter sponge a bit more aggressively than usual. I always keep it submerged in tank water, and only use tank water for cleaning it, but this time I really gave it a good squeeze. I didn't wring it - but a good squeezing.
• I rinsed out the empty plastic filter housing using hot tap water.
• On a couple of nights, I broke the pleco's algae wafer into two pieces, a big one and a small one. The big one went into the pleco bowl as usual (this makes cleanup a snap - and you even get a fair bit of pleco poop out of the tank, too!), and the smaller one went onto the tank floor a ways away. This was done because one of the plecos is the alpha male and constantly chases away the other. I wanted to give the other guy a shot at some algae wafer while the dominant was eating in the bowl. I didn't sweat the lack of cleanup because it was a fairly small piece, and the cories are more than happy to help clean up anything in the substrate.

Does anything in that list strike you as a mistake or potential problem? And whether it does or not, how long does it typically take for things to settle back into normalcy after you've gone astray? Daily PWCs get old fast.

Thanks in advance for your thoughts.

 

Welcome to the forum!

Its great that you started off the right way. You have done everything right so far but the problem I see is with your "big cleaning". IMO there shouldnt be a "big cleaning". You should be siphoning the debris you see everywhere every water change. Even under the decor. With not siphoning the sand under the decor, debris can get trapped under and begin to decay and cause your nitrates to rise. (maybe other things as well.) Also, you don't really want to squeeze your filter media. A good swish in tank water is more than enough. Personally, I don't clean my filter media unless the flow of the water coming out is decrease considerably.

What you probably did is over clean. Over cleaning can be just as bad as under cleaning. It can cause minI cycles like what you are dealing with right now.

Your tank should be back to normal within a week or two. For now, I would do exactly what you are doing (daily water changes) along with an ammonia/nitrite detoxifier like Prime. (note: wait at least 24 hours before testing when using Prime as it can mess with the results.)

 

Welcome from a newbie.Sorry if I'm going off track on your thread but I read your info on Pleco Bowl?this sounds like a way to have less cleanup when feeding. How does it work?I'm a visual learner and any chance of a picture to explain?

 

Welcome to Fishlore. I agree that this mini-cycle was caused by over cleaning. To avoid this, do your filter maintenance on a different day than your water changes and gravel vacs.

 

Welcome to the forum!

Its great that you started off the right way. You have done everything right so far but the problem I see is with your "big cleaning". IMO there shouldnt be a "big cleaning". You should be siphoning the debris you see everywhere every water change. Even under the decor. With not siphoning the sand under the decor, debris can get trapped under and begin to decay and cause your nitrates to rise. (maybe other things as well.) Also, you don't really want to squeeze your filter media. A good swish in tank water is more than enough. Personally, I don't clean my filter media unless the flow of the water coming out is decrease considerably.

What you probably did is over clean. Over cleaning can be just as bad as under cleaning. It can cause minI cycles like what you are dealing with right now.

I do vacuum with every weekly cleaning, but I alternate tank halves. This is a fairly established practice for me that has been working well.

On the sponge: so can you in fact squeeze the bacteria to death? Or just remove too much of it? If so, that may be just what happened. I'm hoping the pre-filter sponge will cut down on the gunk inside the filter and also give me some bio filter redundancy.

I'm assuming the use of tap water for cleaning the filter housing is ok, then?

Thanks for taking the time to reply.

 

Welcome to Fishlore. I agree that this mini-cycle was caused by over cleaning. To avoid this, do your filter maintenance on a different day than your water changes and gravel vacs.

Although that sounds like a very reasonable guideline, my approach to cleaning has not changed in months, aside from the particulars noted in my OP. I'm more inclined to suspect one of these "out of the norm" items as the culprit.

I understand your point, though, and your advice is duly noted. Thanks for replying.

 

Good morning. Welcome to Fish Lore!

Keep in mind that the beneficial bacteria needed to sustain the tanks cycle is attached to all surface areas of the tank and filter with the highest concentrations of it being in the filter.

I think the above members hit the nail on the head so to speak when they mentioned over cleaning. Keep up with the daily water changes and Prime or Amquel + to detox your levels until you are back to 0,0 under 20. Hopefully it will not take to long to regain your cycle. This will keep your fish safe.

I hope you enjoy the forum!

Ken

 

Welcome from a newbie.Sorry if I'm going off track on your thread but I read your info on Pleco Bowl?this sounds like a way to have less cleanup when feeding. How does it work?I'm a visual learner and any chance of a picture to explain?

It's nothing revolutionary.

I have a small Pyrex bowl that I use specifically for this purpose. At feeding time, the algae wafer goes into the bowl and the bowl goes into the tank. This approach has solved several problems for me.

The plecos eat slowly (though not for lack of trying), and the bowl keeps the wafer compartmentalized as it begins to break apart. Then too, plecos produce waste just about as fast as they eat, so a good deal of waste ends up in the bowl (and is therefore removed from the tank when mealtime is over).

The bowl is also a good visual cue for everyone in the tank. When it goes in, the alpha male knows just what it means and is on it like white on rice. I make sure to place it a bit away from the cory feeding spot - the dominant pleco spends most of his energy defending the bowl, which leaves everyone else to eat in peace.

 

A quick update: nitrites are zero again tonight. No PWCs since Monday. So hopefully that's over with!

Thanks everyone for your thoughts.

 

On the sponge: so can you in fact squeeze the bacteria to death? Or just remove too much of it? If so, that may be just what happened. I'm hoping the pre-filter sponge will cut down on the gunk inside the filter and also give me some bio filter redundancy.

You don't squeeze them to death, you remove to much of it squeezing from my experience.

Good luck! Hope your tank stabilizes