Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
The NO2 is probably fine, as long as the tests all seem to indicate ANYWHERE under 5 ppm. The tests are not that accurate anyway.
However, here is how to use them to try to get an 'in between' reading:
API tests say to start with 5 ml tank water.
Do this instead: 2.5 ml tank water + 2.5 ml distilled or RO water. Tap water is OK if there is no NO2 or NO3 in it. Do not use tap water with chloramine if you are doing the ammonia test.
Then double the test result. If the test seems to show it closest to 2 ppm, then call it 4 ppm. You could probably cut that again, perhaps 1 ml tank water + 4 ml of tap, then multiply the result by 5, but somewhere in here you are trying to get an accuracy beyond what the test kit is good for. Interesting to play around with it, and see if the 2 test kits (strip and test tube style) agree.
Excel is probably OK during cycling, but I would not use the loading dose that Seachem specifies, just the regular dosing.
On page 2 of this thread someone asked about the fish-in cycle. It works, but is slow. For an experienced aquarist who understands patience, and is willing to put in that much work, that is fine. But it does take diligence with the water changes. Here is a rough time table:
Set up tank, add a small starter culture of bacteria from any source, probably sharing media from a well cycled tank. Plant with as many plants as you can.
Add a few fish, not to exceed the capacity of the bacteria you have shared. If you have only lightly planted the tank the plants do not count as bio filter. For a densely planted tank see my comments below.
This part of the cycle is not too bad, as long as you have properly estimated the fish:bacteria ratio.
Allow the tank to settle in, plants to get going and get many species of microorganisms growing (transferred from the old tank). Couple of weeks, maybe a month. No hurry.
Test for ammmonia, nitrite, nitrate.
Do water changes if needed. Might not be needed, remember SMALL fish load. Balance with the amount of bacteria.
Add more fish. This is where your fish:bacteria ratio is out of sync. Too many fish for the bacteria. Do not overdo it, but you are adding more fish deliberately. You actually could simple start overfeeding the original fish to supply more ammonia. Fish food is really the source of ammonia in a fish-in cycle.
Anyway, keep on testing ammonia, nitrite and nitrate. You will need to do water changes. Perhaps daily.
When the tank has cycled for that amount of fish (a week or two if you have not added too many) you can add more.
At that rate you will be carefully monitoring and doing water changes for several months while you gradually build up the fish population.
This may be fine, as long as you understand that is what you are in for.
Weekly large water changes (EI fertilizer schedule) usually fit with people's work schedule. Daily water changes (fish-in cycle) might get to be too much, after a long day of work.
Starting an aquarium with dense planting is one of the fastest cycles that can be done. I suggest this for people who already have at least one successful planted tank, so you know how to do it right so the plants hit the ground running.
A densely planted tank (so dense you cannot see the back) will support a reasonably full load of fish from the beginning. The plants bring in a fair amount of nitrifying and other bacteria on their leaves, stems and roots, and the plants themselves are nitrogen sinks. I am not so sure about someone setting up their first planted tank this way, and including a full load of fish. The plants may die, leaving them with a full tank of fish and no bio filter.
The fishless cycle, using ammonia is better for several reasons.
No risk to fish.
The new hobbyist is getting a chance to practice with the test kits.
Gives you longer to think about and research the fish list.
Allows the plants to get better rooted.
Allows the new hobbyist a chance to get to know the plants, adjust the lighting and so on while not relying on the plants as a bio filter.