Plants During A Fish-In Cycle?

[G-skrilla]

Are plants good or bad to have during a fish -in cycle 20 gal tank? If yes, suggestions?

 

[waterdrop]

I think plants are quite a good thing to have during a fish-in cycle, the more the better. In a fish-in cycle you are between a rock and a hard place because you really would like to not give your fish permanent gill or nerve damage by letting the ammonia or nitrite drift of 0.25ppm but the tank is already off and running and does not yet have a working biofilter.

This leaves you being the "manual" filter (and boy can people feel it in their arms if they are lugging lots of buckets of water, lol) through all the weeks while the bacteria slowly build their colonies up to the point of becoming your "automatic" filter.

Plants, especially if there are heavier plantings, will absorb some of the ammonia (and nitrates(NO3) and, quite rarely, tiny amounts of nitrite(NO2)) and thus do some of the work for you, perhaps saving you some volume or frequency in your weeks of water changing.

The trick with plants though is that you must be at least proficient enough to keep them alive and growing. To the extent that they die on you, they reverse the benefit and become a liability, breaking down and providing material for more ammonia and nitrogen products.

~~waterdrop~~

 

[Ashers]

Did the same fish in with plants in a 20gal. I put plants in before the fish by about a week and had no die off but when I was looking for ammonia in a bottle, which I couldn't find for my life, I went to pets at home and the bloke asked me a few questions and when I said that my tank had plants in it he jumped and said that he can't sell fish to me and that my nitrites would just spiral out of control. He was right. I had a real problem keeping nitrites down but after three weeks and a whole bottle of water conditioner I was done.
Good luck!

 

[waterdrop]

That doesn't make any sense to me. Why would nitrites(NO2) be any better or worse just because plants are present during a fish-in cycle?

Many plants will take up ammonia. Many plants will take up nitrate(NO3). A very few plants will take up nitrite(NO2) in small amounts but it's rare. So we don't usually have any expectation that plants will reduce the amount of excess nitrite that happens during the second phase of cycling (when ammonia oxidizing bacteria are producing more nitrite than there are nitrite oxidizing bacteria to handle it.) Likewise, there is no reason that the presence of plants should make the nitrite spikes any worse than they already will be. Each 1ppm of ammonia gets processed in to 2.7ppm of nitrite, way more than a brand new colony of developing Nitrospira can handle, but plants don't make that any worse to my knowledge.

~~waterdrop~~

 

[Ashers]

That's what I thought that he was talking rubbish but I really did have problems with nitrites for some reason.

 

[waterdrop]

Part of it is that a 20g is a small enough volume that the tripling of each ammonia ppm can cause very rapid spikes. A larger tank will give you more time to react.

The skill in fish-in cycling is to keep measuring and adjusting the percentage and frequency of the water changes to keep you in that narrow safty band of zero ppm to 0.25ppm of the poisons, such that you have time to get home again and change water again before you've damaged their gills or nerves. Overshooting on fish-in stocking or having a smaller tank either one can make it a rough task.

~~waterdrop~~