Rarely. It takes more than rinsing media to dislodge the microorganisms. And if a decoration had some biofilm attached to it and it was then covered by algae yhickly enough that you need to scrub it, the microorganisms will have likely have died off by then.
They reproduce based on ammonia levels. If ammonia is increased, they reproduce faster and their numbers go up until they can handle that total mount of ammonia. The reverse works the same way. If ammonia levels drop, then they reproduce more slowly and the total number shrinks. The lifespan of a bacterium is a day. But a colony consits of a lot of bacterium. There are constantly dying and reproducing.
The need to do anything when one has an ammonia reading depends one how much of that ammonia is in the toxic unionized fore NH3 vs how much is in the form of ammonium NHB4 which is way less toxic. Some say NH3 is 100 times as toxic and NH4.
Most of out test kits measure Total Ammonia (
TA) which is the sum of NH3 and NH4. To know how much might be in either form can be done in one of two ways. The first is to have a second ammonia test kit which only measures NH3. Then you can take the TA reading and subtract the NH3 reading from the TA reading and what is left must the amount of NH4. OR you can do something easier. You will need to know both the pH and temperatures of you tank water.
I am assuming here that we are talking about a tank which has no salt in the water or else you will need to know the salinity as well. But I am assuming here that the tank has no salt added to it and it is all freshwater. Then here is what you should do which is from one of the cycling articles on the site says:
Knowing how dangerous any level of TA might be requires that one know not only how much total ammonia there is but also how much of that total is in each form? The answer depends upon two other water parameters- pH and temperature. The higher the pH and/or temperature, the more of the TA that is in the toxic NH3 form. To calculate how much of the toxic NH3 form of ammonia requires that you know what the
pH and
temperature of your tank water are. Once you know all three numbers (total ammonia, pH and temperature) there is a formula for calculating how much of the total ammonia is in the form of NH3. It is way more complicated to use than most of us can handle. Fortunately, there are charts and tables available for this calculation. There is also currently a handy dandy ammonia calculator you can find here:
http://www.hamzasreef.com/Contents/Calculators/FreeAmmonia.php
1. Choose NH (NH3 + NH4)*
2. Enter in the total ammonia reading from your test, choose ppm.
3. For a fresh water tank, enter 0 for the salinity.
4. Enter your tank’s current pH.
5. Enter your tank temperature and choose F or C, whichever applies.
6. Click Calculate.
The number you want to know is the one for
NH3.
[* If your kit measures ammonia as nitrogen aka –N, choose NH-N (NH3-N + NH4-N) in step 1. above.]
Why do you want this number? Because, to get a tank cycled you need to have ammonia (and nitrite) present and you want to have as much total ammonia present as possible without causing permanent harm to the fish. And it is the NH3 that will cause the real harm. Your goal is to allow the total ammonia to rise as high as possible as long as the NH3 content does not get to .05 ppm using that calculator. And even if that level of NH3 is not reached, there is still a limit to how high one can allow total ammonia to rise.
Remember, NH4 can still cause ammonia burns. This writer’s normal cutoff for total ammonia for more than a few days or so is 2 ppm. As a rule of thumb, you can run at 2 ppm of total ammonia with the NH3 being well under .05 for some short amount time. The lower it is under .05, the better. At under .02 ppm of NH3 many fish can be in up to 2 ppm for a number of days and still be OK. The best sign of how long is how the fish behave. If they act distressed, then that is high and/or long enough. Some fish can manage in higher levels, others can’t. This is why you must also watch the fish as well as the test levels.
Hint: As a rule, problems from ammonia become increasingly serious as one’s pH goes above 8.0 and by 8.5 one must really be doing a fishless cycle only. This is very relevant for those keeping rift lake cichlids
There are two goals in fish in cycling which are diametrically opposed. One is to allow ammonia and nitrite to get high enough to get the cycle done as quickly as possible. The other is to keep the ammonia and nitrite from being high enough to cause permanent harm to the fish. Every water change slows the cycle. But the failure to do one at the proper time can harm or even kill the fish.
SIGNS OF AMMONIA POISONING
Fish will not behave as they normally do. Signs of ammonia poisoning can include sluggish behavior, panting, and gill discoloration (gill burn). Fish may hang just below the water surface or they may hide or stop eating. When you know you have ammonia in the tank during cycling and you notice such behavioral changes, the best course of action, regardless of test results, it to do an immediate water change of 50% or more.
The sake articles explains why one does not need to change water when nitrite is present as adding a bit of salt qwill prevent the nitrite fron getting into the fish and causing the blood not to be able to carry oxygen. The articles is here:
https://www.fishforums.net/threads/rescuing-a-fish-in-cycle-gone-wild-part-il.433778/
