nitrogen cycle stuck?!

Hello all. First of all let me say thank you to everyone on here, if it weren't for all of you I would of lost more fish in the last 10 years......don't want to even think about it.
Secondly, my 120G crashed after 8 years, still no idea what happened but after 6 months of trying to get it turned around I decided to start right from scratch.
Here is what I did,
1) Emptied all water, took out all decorations, heater, filters pumps, etc.
2) I was left with 1.5" of sand in a bare tank.
3) I used a solution of 20:1 (water:bleach) to clean the tank with the sand still in it.
4) I swashed the sand around with this solution and let the sand "soak" for a couple hours.
5) While the sand was soaking, I took all filters, heater, pumps and decorations and washed them with the bleach solution.
6) Went back, swashed the sand around again and drained.
7) filled the tank 1/4 full with tap water and swashed the sand all around, drained.
8) Did step 7 x 5 times (rinse and repeat)
9) Once all decorations, filters, sand, etc were cleaned and rinsed to what I thought was sufficient, I started putting it all back together.
10) I through out all filter media.
11) At this point I must tell you that before I started all this work, my tank had a garbage bag full of java fern and red amazon swords.
12) I did a 40:1 bleach to water solution and dipped only the plants I wanted back in my tank to rid any bacteria or whatever that may be on them.
13) So, now the tank is filled with water, (used Prime for my dechlorinator), brand new filter media.
14)I have 2 HOB aquaclear 110's. 1 filter has sponge, filter floss, charcoal and the other one has half a sponge, filter floss and a huge bag of fluval ceramic rings.
15) Let the cycling begin! No fish, just 6 medium sized red amazon plants and 3 large clumps of java fern.
16) oh and I guess I should mention that I had 1 bala shark left over from the crash and kept him in a bucket.
17) So, May 28th, the day after the tank was filled, "primed" etc. readings were .25 ammonia, 0 nitrite, 0 nitrate. ph was 6.4. I live in an area with very soft water so basically kh and gh are zero at all times.
18) Every day the readings were exactly what was expected. Ammonia was climbing and reached 4ppm in a week with 0 signs of nitrite and 0 nitrate. ph was stable at 6.4.
19) I waited for 3 days before testing again, Ammonia dropped to .25 and nitrite was 0, nitrate was 5.
20) I thought wow, that change happened fast! woohoo Time to put in the bala shark!
21) Bala Shark seemed good for a couple days and the readings stayed the same.
22) 25% water change
23) Readings still the same.
24) about 1 week after the bala shark went in, I added 8 small bleeding heart tetras. All seemed fine.
25) Ammonia started to rise to .5 which I expected so I did another water change.
26) Added 8 corys.
27) repeated step 25 and 26.
28) All seemed good with water changes BUT.....
29) after 1 week of adding the corys, 6 of them died. The tetras are all ok and doing well.
30) At this point I will say I haven't seen my amazon plants grow this fast before.
31) So today this is where I sit. Ammonia now 1ppm, Nitrite 0ppm, Nitrate 5ppm.

It's been 2 months and no sign of nitrite and I cannot get the ammonia down. Getting a little tired of the water changes.
I have not cycled with plants before but not even sure what to do or if the plants are affecting the readings?. Is my nitrite test kit not good? I use API liquid tests.
I tested my tap water and it says .5 ammonia, 0 nitrite. (haven't tested nitrate).

Any comments, suggestions, information would be greatful. Thanks for your patience in reading this long winded thread but wanted to give you as much information as possible.
I couldn't find any before pictures but the tank was FULL of java fern so you couldn't see much anyways.
I am attaching a picture I just took.

sumthin fishy said:

Well first off, I would say the long winded post is a lot better than "my amonia is xppm and nitrate is Yppm so whats going on"

This is odd, I have not tried cycling with plants, and Im no plant expert. If you could peruse the plant forum and see if plants consume nitrite, it would say the plants are eating the low levels of nitrite before the nitrite eating bacteria can become established. This would explain the surge in growth, but is speculation on my part. I would also suspect your test kit at least a little. Take a sample to your LFS with your test kit and have them do a test while you do the same and see if they are close.

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My next step was to do just that sumthin fishy.... go to the LFS and get my water tested. I am looking into the plant situation. Thanks.

gmh said:

How did you add ammonia to cycle the tank? You never had nitrite or nitrate readings so I suspect the ammonia was not added consistently and the the tank is still cycling and the new fish are paying the price.

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I started the cycle with 1 bala shark. He was the last fish left from my crash and managed to save him before I "re-booted" the tank. Like I said, after I saw 0 nitrite and 5 nitrate, I added the tetras. So, it was a fish cycle. I have been doing water changes quite frequently and adding prime. I haven't lost any of the tetras and it's been about a month since I put them in there. So, I guess I'm confused as to why the ammonia won't go down, I haven't seen any nitrites but have a consistent nitrate reading of 5ppm.

Glabe said:

Along the lines of this, 4ppm ammonia in a 120g is a lot of ammonia. (Steps 17-18)

Have you been consistently checking your ph and kh? A low kh can potentially lead to disaster since the nitrogen cycle tries to drop ph, and kh is your buffer to keep your ph up. If your kh hits 0, your ph is free to drop as is pleases, which can halt your cycle.

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wow, interesting. My kH is 0 all the time, I have not had a reading of any kH since I've had my tank.....which is over 10 years now. In saying that, I have not been consistent in checking the pH. In the first week it was every day and it stayed around 6.4. Then I checked once a week for a month and it has been 6.4 every time. It's been about 3 weeks since I checked it.........Let me check right now........ok, it has definitely dropped. It looks like 6.0 or even less, ( my card does not go lower than that). Time to check on how to keep pH and kH stable.
Thanks Glabe. :thm:

Byron Amazonas said:

Well, I may be able to offer some suggestions/advice.

First, on the ammonia. This may be occurring from residue of the bleach. Never, ever use bleach on porous substances like wood, rock or sand/gravel because you cannot be sure of getting all of it out. And, always air dry any item cleaned with bleach before placing it back in the water (filter tubes, pythons, tanks, etc). I don't know why you resorted to bleach but in such cases toss out the sand and use new sand, it is much, much safer.

With acidic water the ammonia is not toxic ammonia but ammonium which is basically harmless so this will not cause issues. Our test kits like the API read ammonia/ammonium as "ammonia" so don't worry there. However, you shouldn't be seeing any, which is why I am thinking the bleach. [I assume you have tested your tap water for ammonia (and nitrite and nitrate)? Just in case.] Plants need ammonium as their preferred source of nitrogen, so they will grab this (or should, depending how many plants and what species). Aside from the bleach issue, from what you have set out the tank should cycle itself with zero ammonia, zero nitrite, and very low nitrates (< 5 ppm, often zero until the organics get going in the substrate). I set up all my tanks using live plants. Java Fern is not going to use much ammonia, being a slow growing plant, but Echinodorus (swords) will. And yours seem to be if they are growing fast as you mentioned.

To the GH/KH and pH. I am in Pitt Meadows, just down the road from Mission, so I am well up on our water. GH and KH is about 7 ppm which is less than 1 DGH and basically zero. The pH out of my tap runs 7.0 sometimes 7.2 (they add sodium carbonate, = soda ash). In the aquaria, it varies depending upon other additives I use from 5 or lower to 6.4 or thereabouts. I do nothing to buffer the pH, and I do nothing to add KH. I only have soft water fish so this is no issue. If you intend moderately hard to harder water fish (livebearers, rift lake cichlids, etc) you will need to increase the GH and pH. I won't get into that. But with soft water fish like those mentioned, you're OK as is.

The issue of nitrifying bacteria being hampered by the low pH is a valid one, but it has never given me any problems.

One thing about our very soft water is a lack of the "hard" minerals such as calcium, magnesium, etc for plants. I find my larger Echinodorus need additional supplementation beyond what liquid fertilizers and even substrate tabs can give, so I use Seachem's Equilibrium in three tanks that have the larger swords, Aponogeton and Tiger Lotus. I raise the GH to around 5 or 6 dGH which is sufficient for the plants but not too much for the fish. Most of my soft water fish are wild caught.

To the cory problem. This could well have been bleach residue in the sand. Corydoras have a very high intolerance for ammonia, and of course any bleach in the sand is going to affect them primarily as they sift through it continually. Could be other reasons though. What species? If they were wild caught, they are best going into an established aquarium. May have more when I know the species.

Feel free to ask further.

Byron.

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Great advice and input Byron, thanks. In regards to the bleach......2 reasons why my simple brain thought it would be best to use, #1) If there was some weird bacteria or fungus that caused my crash, the bleach would kill it. #2) If some small amount of bleach was left behind, it would kick start the cycle process. I guess it would of been better to use new sand. I'm a cheapskate and thought this would be ok. Lesson learned. I will get some new sand. BTW the sand I bought was pool filter sand from a place on Lougheed highway in Maple Ridge. In regards to the decorations, they were all air dried outside before placing in the tank.

With my test kit, it shows .5 ppm ammonia (or ammonium) from the tap, 0 nitrites. I have not tested Nitrates from the tap.

My pH was at 6.4 and now seems to be around 6 or lower.

I had 4 pepper corys and 4 julliis. I lost all pepper corys and 2 julliis.

So right now water parameters are = pH of approx. 6, 1 ammonia, 0 nitrite, 5 nitrate
inhabitants = 8 bleeding heart tetras and 2 jullii corys. 6 red amazon swords and 3 bunches of java fern.