Might be my lucky day (cycling progress)...

[zackish]

Ok, I have had my tank cycling for exactly 9 days...I have 0 ammonia, 2.0 or so nitrites, and about 40 nitrates.
Someone said I could do a massive water change and i'm done, is this correct or wait a few more days?
By the way I used the fishless cocktail shrimp method.

Also, if it is done being cycled, can I leave the shrimp in there to keep producing ammonia blah blah blah and going through the cycle until I get my fish wich won't be until early next week?

[cocoa_pleco]

its safe to do a water change, and the shrimp can be left for ammonia production

[zackish]

So does that mean I'm done and I can start adding fish?

[cocoa_pleco]

pretty much. dont overboard though. too many fish at once can shock the system and be too hard a workload for the bacteria. gradually add fish

[bscman]

pretty much. dont overboard though. too many fish at once can shock the system and be too hard a workload for the bacteria. gradually add fish

I think it's dependant on the ammonia levels that were added.

For instance, the reason you add 3-5ppm of pure ammonia to a tank during fishless cycling is because, generally, that would be MORE ammonia than a normally stocked tank could produce. This means, by the time your tank is done cycling, you can fully stock your tank right away....all that ammonia you kept feeding them caused a HUGE amount of bacteria to colonize...this means they are more that able to handle the full bioload from a stocked tank right away.

This is the great thing about fishless cycling.

When you added your shrimp peels, did you monitor ammonia levels through the whole process? What was the highest they reached?

These questions will result in how much fish you can add, and how quickly you can add them. If it was over 3ppm, you should be safe fully stocking the tank. If not, it would be best to slowly stock the tank.

Here is where things get tricky, though. If there is not enough ammonia in the tank some of the bacteria will start to die off from lack of food...so then, when you go to add more fish you'll be starting a mini-cycle because now the bioload is more than the current bacteria can handle...and it will stay that way until the bacteria colonies grow large enough to handle the larger bioload.

So if you did a fishless cycle by keeping the ammonia levels at 5ppm...but then took away the ammonia, the bacteria die off very quickly.
If you remove the ammonia source, and only add two small fish, *most* of the bacteria will die off and only some will survive because there is not enough food to go around. Then, when you go to add fish later, again you mini-cycle until the bacteria can catch back up to the bioload.

It's a fine line, and you have to pay close attention to every detail. :c3:

[zackish]

Yes I did monitor my ammonia levels and they were off the charts well over 8.0 ppm. I also added 2 more shrimp and I have 0 ammonia still so I think my bacteria is pretty strong...

[RobbieG]

If its going to be a while til you can add fish you pretty mcuh have to keep the shrimp in there for ammonia or the bacteria will die off. You can do the water change today (and probably another shortly before you add the fish)

You should have enough bacteria built up to handle a good sized bioload - but make sure to choose your fish based on how big they will get not how big they are (I'm sure you know that, but JIC)

[Lady Hobbs]

As long as you still have nitrites, I would not consider your tank fully cycled. Give it a few more days and keep the source of ammonia going. Your tank is done when ammonia is 0 and nitrites are 0.

[zackish]

Ok and if I am not adding my fish till early next week can I just leave the shrimp in there and do the water change like a day before I get the fish?

Also, can I do a near 100% water change?