Is my tank nearing cycle completion?

[ALAW]

Hi all just after a bit of advice if possible.
I started a fish in cycle after a failed fishless cycle (let ammonia get too high, stalled)
I conducted a huge water change and restarted using Tetra safe start to help the cycle process shortly after introducing 2 Mollies.
I've been monitoring the water conditions for a few weeks with Api test kit.
Ammonia slowly climbed and I've never had traces on nitrite (apparently Tetra SS skips this bit) and have had very very small traces of nitrates from the get go.
Anyway, ammonia climbed to 2ppm so I conducted a 50% water change, this reduced the ammonia to 1ppm, with no nitrites and hardly any nitrates.
5 days later I noticed a brown algae bloom so i tested the water today, results show ammonia has decreased to 0.50ppm, nitrites 0ppm and trace nitrates.
Would anyone agree with ammonia decreasing the tank is nearing completion? Even with the nil nitrites and probably 1-2ppm nitrate?
Any help is appreciated.

 

[Essjay]

The cycle has finished when you have a week of zero ammonia and zero nitrite. But the tank will only be cycled for the fish currently in the tank. If you add a lot more fish at once, you will find the tank undergoing another cycle. Adding fish slowly, a few at a time, and waiting for a week of zeros before getting the next batch is the safe way to go.

Any ammonia reading of over zero needs a water change to get it down - but there may be a bit of leeway depending on the pH. Nitrite, if that does show up, needs to be kept at zero by water changes.

 

[ALAW]

OK thanks, I was happy to see ammonia had reduced, but expected to see a rise in nitrates, something has to be reducing the ammonia, I will monitor closely.

 

[Sgooosh]

OK thanks, I was happy to see ammonia had reduced, but expected to see a rise in nitrates, something has to be reducing the ammonia, I will monitor closely.

its the bacteria that means it is good. nitrate is good for plants

 

[Essjay]

You didn't mention in the first post whether or not there are live plants in the tank. If there are, that's one explanation for your readings. Plants take up ammonia as fertiliser and they turn it into protein and not nitrite or nitrate.

 

[Sgooosh]

You didn't mention in the first post whether or not there are live plants in the tank. If there are, that's one explanation for your readings. Plants take up ammonia as fertiliser and they turn it into protein and not nitrite or nitrate.

live plants cycle the tank faster and look better but are expensive haha

 

[Maff]

The cycle has finished when you have a week of zero ammonia and zero nitrite. But the tank will only be cycled for the fish currently in the tank. If you add a lot more fish at once, you will find the tank undergoing another cycle. Adding fish slowly, a few at a time, and waiting for a week of zeros before getting the next batch is the safe way to go.

Any ammonia reading of over zero needs a water change to get it down - but there may be a bit of leeway depending on the pH. Nitrite, if that does show up, needs to be kept at zero by water changes.

There's a flip side to that coin. My friend and I both started tanks this month. He went for a fishless cycle and I preferred an in fish cycle because that's where I've had experience in the past.
We both used filter media from a friends established tank but I also added bacteria gel balls as a supplement. He used ammonia as a source and I used fish.
His cycle went fairly well, he hit some big numbers in the ammonia stakes (4ppm) and got it back down reasonably well without water changes, he hit the nitrites as per planned and got them down, finally he hit 0 ammonia and 0 nitrites for several days and planned for fish after his water change. He added three small Danios and two Platties then wham, he's hit with 1ppm ammonia in the first 24 hours and having to do water changes.
What happened? Only three things could have caused it IMO. He left it too long after his last ammonia went into the tank and the bacteria culture reduced OR adding chemical ammonia to the tank cannot simulate what comes out of a fish OR most of his bacteria went with the water change. He assured me it was less than 48 hours after the last ammonia went in the tank and the introduction of fish. I cannot see 48 hours being long enough to deplete a bacteria culture so you end up with 1ppm after 24 hours of fish. His last two readings on the two days before the fish were zero and zero. Many people have done successful fishless cycles without any problems yet over the past few weeks I've read many others experiences where they complete a fishless cycle then add fish and it goes wrong. IMO the problem lies not with bacteria numbers that can deal with pure ammonia but it lies with their ability to break down other substances such as fish faeces and uneaten food. There are other processes going on in a tank full of fish that are not going on by adding pure chemicals and I believe that you can breed a very weak biological barrier against it by trying to simulate it if you are not careful. That's why many prefer the dead shrimp method over chemicals because your biological system learns to deal with more complex decomposition.

 

[Essjay]

What happened? Only three things could have caused it IMO. He left it too long after his last ammonia went into the tank and the bacteria culture reduced OR adding chemical ammonia to the tank cannot simulate what comes out of a fish OR most of his bacteria went with the water change.

4th option - did he do a proper fishless cycle? Did he add doses of ammonia whenever the ammonia and nitrite readings reached certain targets? If he didn't, he won't have grown enough bacteria.
Without knowing exactly how he carried out the cycle it is impossible to say.

 

[Maff]

4th option - did he do a proper fishless cycle? Did he add doses of ammonia whenever the ammonia and nitrite readings reached certain targets? If he didn't, he won't have grown enough bacteria.
Without knowing exactly how he carried out the cycle it is impossible to say.

He was using Dr Tim's kit and followed the instructions to the letter and everything went fine and the tank cycled. Ammonia 0, nitrites 0 and nitrates building nicely for days. He had good numbers for days then added a small quantity of young fish and hit 1ppm ammonia after 24 hours. He's not the only person this has happened to, I've read at least a dozen accounts of similar circumstances and it put me off fishless cycles. If you do a fishless cycle and hit a peak of 3-4ppm ammonia without a stall and you get it down to zero along with nitrites and after you add more ammonia each day then the bacteria culture looks healthy and strong, there should be no way a few fish should be able to spike it unless you put ammonia in along with the fish. But for some reason it did and he's not the only one it's happened to.

 

[Essjay]

I've done two fishless cycles and not had a problem. But I didn't use Dr Tim's method, I used the one on here. Both cycles took 7 weeks to complete.
I've not read of anyone else having a problem after doing a fishless cycle, so either no-one I've read of has had a problem, or they've not admitted it.

 

[Maff]

I've done two fishless cycles and not had a problem. But I didn't use Dr Tim's method, I used the one on here. Both cycles took 7 weeks to complete.
I've not read of anyone else having a problem after doing a fishless cycle, so either no-one I've read of has had a problem, or they've not admitted it.

Here's one account, I've read many more.

Ammonia spike after fishless cycle

Hey everyone! I just started a new tank and I did a fishless cycle using dr. Tims aquatic live bacteria and pure ammonia. I followed the directions per his website. I was very pleased with the results during the time of fishless cycling. Every time I dosed the tank with pure ammonia it would...

www.aquariumadvice.com

 

[Essjay]

That's another person using Dr Tim's method.

Both his method and ours start with the same amount of ammonia, but the method on here says to add ammonia when certain targets have been reached, and nitrite is allowed to go higher than 5 ppm. Dr Tim's method appears to say to add a small amount of ammonia every few days without waiting for specific targets, and that nitrite should be kept under 5 ppm.

On this forum, we always refer members to our method not Dr Tim's and our method would appear to be more successful. Either that or members are just not reporting problems.