Weird Cycle Results

[Haywire]

So, I've been getting some odd results from cycling and I'm not entirely sure what to do with them..

Some Background
Okay, so. I set up my tank with cheap gravel and potted aquarium plants + decor/rocks etc. I began cycling it (didn't go beyond the first ammonia dose) when I had a snail outbreak. Frustradley, I took everything apart and threw out the gravel and plants. I let everything dry out for over a month and cleaned all the decor thoroughly. I replaced the carbon filter media in both filters and washed all the other media with warm tap water (I accepted most of the bacteria to be dead by now anyway) and washed the tank down with a vinegar/water solution. I put in higher quality black gravel, decorations, rocks and planted some tissue culture plants. Other than some fluffy algae on the gravel that can be vacuumed away, everything was going fine so I started the cycle.

The Results

Before I had started the cycle, I appeared to have some nitrite in my aquarium. Without thinking too much of it, I dosed enough ammonia to achieve 3ppm. On day 4, my ammonia was down almost completely but to my surprise so was nitrite. There was also very little nitrate. I had performed one water change, but it was no more than 10-15%. Naturally, I brought the ammonia levels back up to 3ppm and tested the day after (doing a very small water change when I vacuumed the gravel). Ammonia had dropped by about 50%, whilst nitrite was still 0 and nitrates were low. I am only on day 5 and plan to continue testing, these results just seem very unusual to me. The testing kit I am using is the API Master Test Kit and I'm being very careful to follow instructions properly and retested a fair few times with same results.

Could someone explain these results to me? I'm following the cycle guide on these forums but the results I'm getting just don't match what I should be seeing according to the guide.

Aquarium Specs:
Rio 180
2x Filters (Bioflow 3.0 + tetra 800 plus external filter)
Small black gravel
2* rocks, 2 decor items + tissue culture plants
TNC Carbon + Flourish plant food

 

[hobby5]

If you cycle with plants things are different, you cannot follow the standard protocol. Plants will use ammonia as nutrient. But high ammonia is toxic for plants too. If I remember correctly you shouldn't go above 2 ppm. Personally, I would not go above 1 ppm.

 

[Byron]

I agree. Plants, especially any relatively fast-growing species, can take up quite a lot of ammonia, and that is where most of it is ending up, as nitrogen for the plants. I also agree that as ammonia is toxic to all life forms depending upon the level, with live plants you should be easy on ammonia, even to the point of not adding it at all. The tank will still cycle--some refer to this as a "silent cycle" because you cannot detect nitrite at all, and sometimes not nitrate for months if at all. When I have live plants in new tanks (which I always have for 20+ years now) I have never deliberately "cycled."

If your pH remains on the acidic side, "ammonia" will be primarily ammonium, which is basically harmless to fish. Provided you do not dose further pure ammonia, and you do several water changes to ensure it is gone, fish could be added (assuming the plants show signs of growth) and you are all set.

On the snails, that was rather extreme for no useful purpose. These small snails like pond, bladder or Malaysian Livebearing, are very useful in an aquarium. They get everywhere, eating all dead organics (including fish excrement) which breaks it down faster for the various bacteria. I have hundreds in my tanks, gladly. Those mentioned do not eat healthy live plants.

Last comment...bacteria (the nitrifiers) do not die off as rapidly as many think; they can go into a sort of dormant state for several months, depending upon various factors.

Byron.

 

[Haywire]

-Shortened-

Thanks for the detailed response. I was completely unaware that plants affect the cycle so it's nice to have that cleared up. However, as I won't be adding fish for at least another 3 weeks I'm wondering what the best course of action is to ensure the biofilter is established? I understand that the plants will keep ammonia and nitrite levels down but my tests results show that at the current state it takes 3 days for ammonia levels to drop from 3ppm to below 0.75ppm. I don't believe this will be enough to properly manage the bioload of the two fantails I plan to purchase. What I'm saying is, would something like bringing ammonia levels back up to 1.5ppm whenever they drop below 0.75ppm be an efficient way of encouraging bacteria colonies to multiply without having too much of an effect on the plants? If that's a bad idea, what would you suggest to do over the next few weeks prior to adding fish?

My pH has since climbed to about 7.5 and is staying there. I imagine the only reason it was on the acidic side on the first day of testing was due to the vinegar I used to clean the tank.

As for the snails, the type I had were bladder and as useful as they may be they were laying eggs everywhere and covering the aquarium glass; very unattractive. It wasn't just the snails that prompted a tank tear down, the plants that I was persuaded into buying at the fish store were in very bad shape due to poor advice from the employee there and algae was getting somewhat out of hand. Not to mention the gravel I used was very dirty (despite about 3 hours of cleaning) and unattractive in my opinion. It was nice to rebuild the aquarium in such a way that I can be proud of it and to have all the necessary equipment to take care of the plants.

 

[Byron]

Assuming these are fantail goldfish, they will produce waste more than small fish, though I assume you will not be buying full-grown fish (6-8 + inches). I don't know what plants (species and numbers) you have; faster-growing plants (floating, stem, or several plants like swords) will take up considerably more ammonia than slow growing like Java Fern. The already-established nitrifying bacteria can reproduce by binary division every 12+ hours for the Nitrosomonas sp. (taking up ammonia) and up to 32 hours for the Nitrospira sp. (taking up nitrite, of which there will be less as the plants use ammonia without producing nitrite).

I myself would never add ammonia to a tank with plants. That is just my perspective.

Byron.