Planted Tank + Ferts Fishless Cycle

[BenPursglove]

I have set up my first planted tank with pressurised CO2 & adding approx 1ml of TPN+ daily. The plants have not seen much growth but not surprising as it's only been planted for a week or so but some of the HC is pearling already . I think it's going to be good once it gets going, however...

4 days ago I thought it would be a bright idea to start to fishless cycle the tank with ammonia (addonce method) as I am also wanting a nice shoal in there. I got the water up to 5ppm of ammonis. Today, out of curiosity I did a test and noticed ammonia had reduced (obvious the plants are having some - too soon for the cycle to have started yet). As still curious I tested for NitrIte and NitrAte and they are both very high / off the scale which I attribute to the TPN+, two questions for you:

1. Am I right that the nutrients in TPN+ will register on the tests (NI's - API, NA's - Nutrafin)?

2. If I'm right on point one, how the heck do I know when the cycle is kicking in / completed?

I'm sure that other peeps into planted go with a pre-cycled filter (which I don't have) so am loving to get any input.

Thanks in advance.

BP

 

[RadaR]

Shouldn't register on test kits. Has never done in my experience. There was some hoo-haa about there being a detected ammonium level, but test kits test for ammonia.
Nitrate liquid test kits aren't accurate anyway
If you've got a planted tank that has 75% coverage with plants then don't bother with adding ammonia. You will just get algae. Ammonia+light= algae.
Plants will absorb quite a bit of fish waste and it's broken down compounds(nitrite and nitrate).
Wait maybe a week, then a small shoal of fish could be added, or shrimp. Slowly stock up from there.
Plants are great filters themselves. Although I always recommend a good filter.

 

[BenPursglove]

Thanks for the reply RadaR, I have already added the ammonia and also noticed an algae growth shock horror so what should I do - water change or wait it out? Thanks again

BP

 

[RadaR]

In my opinion I would do water changes to reduce it. Then when the test kit says there is a reading of "0", then you can stop doing them so frequently.
On a high-light system or a nano then do 50% water changes per week. If lower tech then maybe 25% a week.

 

[BenPursglove]

In my opinion I would do water changes to reduce it. Then when the test kit says there is a reading of "0", then you can stop doing them so frequently.
On a high-light system or a nano then do 50% water changes per week. If lower tech then maybe 25% a week.

I can cope and agree with the 50% changes till Ammo's reach 0 but in the post before you seem to be pointing towards a fish in cycle - am I right?

I understand the logic with the plants and all but is this the way folks normally go about getting the cycle going in a planted tank? If so can you have a look at my project log and help to ascertain if I have heavy enough planting to make this happen? Log Here If not, what else would you suggest please?

 

[RadaR]

In my opinion I would do water changes to reduce it. Then when the test kit says there is a reading of "0", then you can stop doing them so frequently.
On a high-light system or a nano then do 50% water changes per week. If lower tech then maybe 25% a week.

I understand the logic with the plants and all but is this the way folks normally go about getting the cycle going in a planted tank?

Yes.
It's catching on because it works well. Fishless cycles with ammonia when the tank is planted up and the lights are on, doesn't mix well. You get algae. Fishless cycles should be done in the dark (avoids algae and I'm not 100% certain, but I think the bacteria appreciate the darkness, therefore cycle is faster).

Looking at your tank currently, I would be tempted to include some floating plant just for now to be on the safe side. Tropical hornwort, or Elodea.
Combined with the other plants, they should grow well and utilize any ammonia before it gets to dangerous levels. Once plants are noticeably growing well, add small shoal.

 

[Craster]

While not wishing to dismiss those who use the 'heavily plant and go' approach, I personally don't advocate it.

Lots of plants are a great thing for using up toxic ammonia - but do not really do much at all about nitrites, and in hard water (which I have), nitrates are quite a bit more toxic than ammonia is (which tends to form ammonium pretty quickly). I have always also been confused about how your bacterial colonies form if the plants are taking up all the ammonia - either:

The plants don't take up all the ammonia, so there's enough for the filter colony to reproduce.

or

The plants take up all the ammonia, so there is no bacterial growth in the filter.

In the first case, the plants nicely control the ammonia, but you're still faced with the second half of a fish-in cycle as the bacterial colony required to convert nitrites->nitrates form. In the second case, you have no bacterial colony at all, which is fine as long as your plant mass is capable of fully handling your load, but leaves me with a decidedly uncomfortable feeling.

I don't want to try and correct the experts here, and I'm quite probably wrong about most of this, but I personally have never had any serious algae problems doing a traditional fishless cycle in a planted tank.

 

[RadaR]

Plants can utilize the Nitrogen in ammonia, nitrite and nitrate. The majority prefer to obtain it from nitrate however there are some that prefer it from ammonia. Algae loves ammonia.
Despite the plants preventing dangerous build up of ammonia, the filter will still contain a colony of nitrifying bacteria because there is still some ammonia present. Hence why we still recommend good filters with good biological media in planted tanks.
So yes,

The plants don't take up all the ammonia, so there's enough for the filter colony to reproduce.

This is correct. Not all the ammonia is absorbed by the plants, but enough to prevent a toxic build up to fish. On a hobbyist's test kit, any ammonia reading is too much. However those are calibarted to show "0" when the level is safe for fish. It isn't actually "0" otherwise the nitrogen cycle wouldn't work.

 

[Craster]

Then in that case, you must end up with the second part of a fish-in cycle - The part where ammonia is being processed, but nitrite is not. There are very few plants that will take up nitrite in any kind of quantity, and it's just as poisonous to fish as ammonia - more so in alkaline water.

This is why I have trouble with the science of this method.

 

[RadaR]

Because there is a small concentration of ammonia being broken down by the filter, it will obviously then result in small concentrations of nitrite. Enough that it can initiate the development of the bacteria that break it down to nitrate, but not concentrated enough for the nitrite to be toxic to the fish.

 

[Craster]

I guess that makes sense. So what you're actually saying is that you're doing a standard cycle on the filter, but blotting out 90%+ of the pollutants before they ever get there.

 

[RadaR]

Sounds good.
There may be more to it than that, however I think that's the majority.
If you wanted a more scientific, somewhat complex explanation, I know someone you can contact.
Let me know by PM and I'll give you the details (he's on another forum and so I can't post it here).