does adding plants speed up cycling?

I guess it depends on where the plants come from. If you stick 4-5 plants from an established tank, it should help some.
 
The bacteria from the cycling will still grow at the same rate. But if the plants have some bacteria on them (as was mentioned) this will obviously be a good thing. Also if they are stem plants they will use a lot of the ammonia before it builds to toxic level, thus lessening the severity of the cycle.

Still if you are going to have fish in the tank during the cycle you must have test kits and rely on water changes and not plants to do the work.
 
YES

Yes, it speeds up the cycling. But, it depends...

If the plants are growing it speeds up the cycling, if they have light and CO2 they will help a lot.

If they are in bad light, they are not growing, not using nutrients. Then while you may have the benefit of the bacteria the plants support on their surfaces, it still ain't much.

If they are dying they are adding to the ammonia, not subtracting it.
 
As anonapersona indicated, the effect of plants is highly variable depending on the conditions and the plants.

Plants do not really speed the cycle as much as they bypass it. Healthy actively growing plants will uptake ammonia for their own use, so that part of the tank-generated ammonia never feeds the bacteria and is not converted to nitrite. If you have enough plants and the right light/CO2/ non-nitrogen supplements, etc, your plants will out-compete the bacteria, but the bottom line is reduced ammonia titer, no nitrite, no nitrate.

But if there are too few plants, incorrect light, no nutrient balance - then the plants will do little or nothing.

If the plants are unhealthy and degenerating, they will contribute to ammonia/nitrite/nitrate.
 
Plants do not really speed the cycle as much as they bypass it. Healthy actively growing plants will uptake ammonia for their own use, so that part of the tank-generated ammonia never feeds the bacteria and is not converted to nitrite. If you have enough plants and the right light/CO2/ non-nitrogen supplements, etc, your plants will out-compete the bacteria, but the bottom line is reduced ammonia titer, no nitrite, no nitrate.

Sorry to jump in on your post stunt 101, but I have to ask.
If the obove mentioned situation occured, would the bacteria grow at a retarded pace, or never at all? similarly, if you had an estabilished tank and added good plants, would they eventually starve out the bacteria by using up all available ammonia? Just curious as I'm new with the whole world of plants.
 
I'm in general agreement w/Chuck glad's article, except for a mis-statement on nitrite - plants do not take up or use nitrite at all. Nitrite does occur very briefly in plants when they are reducing nitrate to ammonium, but it is sequestered as nitrate prior to that reduction to avoid the toxicity of nitrite ion inside the cells. Nobody but certain bacteria seems to like nitrite.

On the effect of plants' ammonia utilization on nitrification bacteria, IME the plants far out-compete the bacteria. But over time both the needed forms of bacteria will be present, just not in sufficient numbers to support the tank alone. Which means that if you have a planted tank and want to go FO, reduce the planting slowly or you may have detectable ammonia or nitrite. Which for me means I can steal a filter from a mature FO tank and count on a mature bacterial colony of both types needed, but I cannot do the same from a planted tank. The filter from the planted tank will "cycle" very quickly, but not instantly.
 
Hmmm, I didn't know that (about NO2). I had knew about NH3 being the preferred source and that NO3 was further down. Now that I think about it, I guess that I just made the link in my mind that NO2 must come between the two as an intermediate oxidation state.

thanks.
 
Yup, it does "cost" the plant a bit in energy use to employ nitrate rather than ammonium as a nitrogen source (It must be reduced to ammonium), but not enough to cause the vascular plants a problem. Supplementing with ammonia is asking for problems, not just for the fish present, but also by feeding algae. Interestingly enough, Seachem's 'Nitrogen' supplement is a blend of complexed ammonia and nitrate.

I once though that plants could use nitrite, but it turns out to be too toxic to handle for transport - so use only ammonia or nitrate.
 
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