Water Changes During Cycling - How Much?

[Snowboarda42]

I just got the LR and LS in my tank on Friday, Fluval, PH lighting and everything up and running (waiting for skimmer in the mail).
The tank is a 40Gal Breeder, 40LBS of LS (gonna add more), and 45 of LR.
The lights are always off except the Lunars which are on from 8pm - 9am.

My question is:
How much water would you change during cycling?

I have read that you should do 50% all at once weekely.

I've also read that you shouldn't change it at all until it's cycling (doesn't make much sense b/c where does the Nitrate go?)

And theres always other Percentages as well.

So what would you go with? 0%? 10-15%? 50%? 90%? 100%?

And all at once on one day? Or space it out (i.e. 10% every day for 5 days)??

Just looking for people's experiences/opinions.

 

[Anonymous]

I would do whatever you are going to do once the tank is running. I like to do about 15% every other week.

 

[Anonymous]

I've never changed water during the cycle, but rather would do a 25% change once the nitrites had dropped off. After that, you could start slowly adding stock.

 

[Len]

I've done it both ways in varying amounts. IME, it's never really mattered after the tank got cycled.

 

[saltman123]

I too waited about 4 weeks for my tank to fully cycle and then changed the water.

 

[JOSEPHLB]

My question is:
How much water would you change during cycling?

I'm new at this, but I would think it would be better to just leave the tank alone while cycling. Now, think about that for a moment..

If its a new tank, that is being freshly cycled, you have various things happening and things that need to be done to get those beneficial bacteria for a cycled tank.. in order for there to eventually be inhabited by these bacteria.. you need:

The ammonia to develop..
Then the bacteria converts that over to nitrite..
From nitrite, you then have the bacteria that convert that over to nitrate..
and finally.. nitrate levels rise..

If you change out large amounts of water DURING the cycle you are disrupting the cycle taking place. You need that ammonia in the water column so it can go on to its next step.. If you change some of the water, in mid-cycle.. you reduce those levels..

Once converted to nitrite.. you need those nitrite levels in there.. so the bacteria needed, develop and convert that over to nitrates..
If you change the water.. again.. you are removing the needed component in order for the cycle to continue.

I've also read that you shouldn't change it at all until it's cycling (doesn't make much sense b/c where does the Nitrate go?)

You don't have nitrate, until the cycle is complete. So, it does make sense. At this point, then its approprate to do a water change. At this point nitrate levels are going to rise. This is where you'll experience your algae blooms, if you don't keep the nitrate levels under control.

 

[Snowboarda42]

i just checked yesterday, my nitrates are going up. Its at 5.0ppm right now. The nitrites are at 0, and I dunno about the ammonia since my test is still in the mail.

 

[toastii]

if your nitrites are zero your ammonia should be zero as well

(if you have been cycling the tank.... if this is a newly cycling tank you might have ammonia

but you state you had trates so... you should actually have zero ammonia)

 

[Anonymous]

My question is:
How much water would you change during cycling?

I'm new at this, but I would think it would be better to just leave the tank alone while cycling. Now, think about that for a moment..

If its a new tank, that is being freshly cycled, you have various things happening and things that need to be done to get those beneficial bacteria for a cycled tank.. in order for there to eventually be inhabited by these bacteria.. you need:

The ammonia to develop..
Then the bacteria converts that over to nitrite..
From nitrite, you then have the bacteria that convert that over to nitrate..
and finally.. nitrate levels rise..

If you change out large amounts of water DURING the cycle you are disrupting the cycle taking place. You need that ammonia in the water column so it can go on to its next step.. If you change some of the water, in mid-cycle.. you reduce those levels..

Once converted to nitrite.. you need those nitrite levels in there.. so the bacteria needed, develop and convert that over to nitrates..
If you change the water.. again.. you are removing the needed component in order for the cycle to continue.

I've also read that you shouldn't change it at all until it's cycling (doesn't make much sense b/c where does the Nitrate go?)

You don't have nitrate, until the cycle is complete. So, it does make sense. At this point, then its approprate to do a water change. At this point nitrate levels are going to rise. This is where you'll experience your algae blooms, if you don't keep the nitrate levels under control.

First off

:welcome:

What you stated is one school of thought on the issue. Here is the counter point to that.

If you are starting with fresh live rock you will have some hitchhikers you want to keep alive. Things like pods, bristle worms, and possibly some corals if you are lucky. Doing water changes during cycling will reduce, but not eliminate, the ammonia, etc levels. This will give the critters you are trying to keep alive a chance.

The levels of ammonia, etc do not need to be of elevated levels to establish you tank waste processing system.

Regardless of how you cycle your tank you should always proceed slowly with stocking to give your waste processing bacteria a chance to adjust.

 

[Patch]

No water changes during cycling, just after, one time. You would just interupt the process, it's like dominoes. let them fall. If you already have fish in the tank, ( I couldn't wait and put two cheap ones in so i could have something to look at), then your rock will have to cycle somewhere else. If it comes from the local pet store as "cured", then you can add it safely now. If your rock comes in the mail, you will need to set up a quarentine tank and let he rock cycle too. Yup, another 6 weeks.