cycling question

[therich84]

my ph is 8.4, ammonia went from 0.8 to 0, nitrite is at 0.2, nitrate is 0, alk is at 5(i kno thats high), calc at 400...i also just had a diatom bloom 2 days ago. my question is am i on the back end of the tank cycling.

 

[Killerdrgn]

uhhh question being?

 

[therich84]

accidentally hit enter and posted without asking my question

 

[therich84]

only a week which i know isnt long at all. my rock was cured when i bought it. i dont plan on adding even a cleanup crew for at least another few weeks even if it looks like the cylce is done. i was just wondering

 

[Bob 1000]

What size tank is it??

 

[therich84]

72 bowfront

 

[Bob 1000]

probably not finish cycling unless you abut 100pounds of lr that came from a established tank... Even if so I would think you should hold of any fish or inverts for a while..

 

[basiab]

When your ammonia and nitrites are zero you are cycled but it depends on what you started with. Even cured rock will have a small cycle since there is always some dieoff when moving from one tank to another. But it does not mean that you have a good home for any critters. You can check it out by adding ammonia and see how well the tank gets rid of it. Either add some ammonia or something that generates ammonia like some shrimp (dead). Then test and see how quickly the ammonia and then nitrites return to zero.
It is a good idea to let it get established for a while but you have to add something to keep the bacteria population going.

 

[KathyC]

Would just like to add that cycling is complete not only after your ammonia & nitrites drop to zero, but you also want to wait until your nitrates rise and then drop down to zero (or very close to zero) before you can consider it done.

As Bob mentioned if the live rock came from an established tank, your cycle will go faster and your bacteria can basically feed off of what is in/on the rock.
If the rock came from a LFS - you will actually have to 'feed' the bacteria in order to keep the good bacteria alive. You can do this by putting a small amount (think the size of your fingernail) of flake food into the tank every second or third day.
If the bacteria in the tank is able to absorb the flake food without raising the ammonia level..then you're not adding too much.

 

[basiab]

Would just like to add that cycling is complete not only after your ammonia & nitrites drop to zero, but you also want to wait until your nitrates rise and then drop down to zero (or very close to zero) before you can consider it done.

.

As I understand it nitrates are a result of nitrites being processed by bacteria and the bacteria needed to process nitrates need a deep sand bed. For those of us we that do not have a dsb we either change water to reduce nitrates or we have skimmers to get rid of stuff so that ammonia and nitrites are not produced to begin with thus there is no nitrates.
But in either case Kathey has a point that you do have to take care of nitrates. Get it under .20 if you have fish and close to zero if you have coral.

 

[KathyC]

As I understand it nitrates are a result of nitrites being processed by bacteria and the bacteria needed to process nitrates need a deep sand bed. For those of us we that do not have a dsb we either change water to reduce nitrates or we have skimmers to get rid of stuff so that ammonia and nitrites are not produced to begin with thus there is no nitrates.
But in either case Kathey has a point that you do have to take care of nitrates. Get it under .20 if you have fish and close to zero if you have coral.

Sam..a DSB isn't required to produce enough bacteria to turn the nitrites into nitrates. Happens in all tanks..FW..SW..just different internal tank surfaces become colonized.
They (ammonia & nitrite) actually are still produced but turned over by the bacteria at such a great rate that we don't get readings on them.
That's why the cycling process is so important ..and to allow it to get to it's end point..that's where the balance is

It's usually the nitrates that get away from people due to inadequate skimming, or overfeeding and the like. Plus the amount of detritus that gets stuck in our tanks between the rocks and such. That's one of the reasons water changes are so important..we need to dilute the nitrates..basically.