Water Change After Cycle, Why?

Genomecop

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Morning all. I'm just curious why a water change is done after or close to the end of a tank cycle. Is this a must? I can't recall if in the 'way' past I ever did such a thing.
Thanks
 
One reason, and I believe the main reason, is that at the end of the cycle you should have 0 ammonia and phosphates, and measurable nitrates.

The nitrates can be high.

A water change is an effective way to reduce the nitrates.
 
It is certainly not a must. It just means more nutrients to deal with (and maybe reduced alk), but if you have that under control, its fine.
 
But is this a must?
I personally don't think so, and I didn't do it on my current tank which I started in February.

I dosed NoPox to lower the nitrates quickly, as soon as the cycle ended. I also added 7 fish at that time.

I know a few others who have done the same thing.

Others may see it differently, and that's fine. That's what I did with my 1st tank.
 
Hi all
Im kinda newish too. I have a question on this tpoic as well.

I'm curing dry live rock my ammonia,nitrites,and phosphorus is 0 but nitrates around 30ppm, so should i just do water changes or use biopellets reactor? And do i need to add food to keep bacteria colony alive?
 
Hi all
Im kinda newish too. I have a question on this tpoic as well.

I'm curing dry live rock my ammonia,nitrites,and phosphorus is 0 but nitrates around 30ppm, so should i just do water changes or use biopellets reactor? And do i need to add food to keep bacteria colony alive?
do a water change. I highly discourage biopellets / carbon dosing at this stage. there is no reason. And yes, you need to continue to feed the bacteria
 
Hi all
Im kinda newish too. I have a question on this topic as well.

I'm curing dry live rock my ammonia, nitrites and phosphorus is 0 but nitrates around 30ppm, so should I just do water changes or use biopellets reactor? And do i need to add food to keep bacteria colony alive?
+1 As stated above. If you start out with low nitrates you will have less alage . A new tank has nothing that will use those nitrates. The more you feed the higher they will go. Don't go over board on feeding the bacteria. A pinch of flake 1 time a week is enough.
 
On my latest tank setup, I pretreated and cycled all my rock outside of the DT. I did a very fast aggressive cycle with ammonium chloride because I didn't mind if the nitrates in the Brute went sky high (and they did.) Now after 4 months, the tank is moderately stocked with corals and nems (and some fish), nitrate is just starting to creep above 1, rocks are covered in coralline growth, and I haven't had any kind of nuisance algae problem to speak of. No massive water change. I'm even holding off on implementing my 'usual' water change schedule with this tank for now, as I see no point with these numbers and happy critters. I will be doing all of my rock curing outside of the DT from now on.
 
Hi all
Im kinda newish too. I have a question on this tpoic as well.

I'm curing dry live rock my ammonia,nitrites,and phosphorus is 0 but nitrates around 30ppm, so should i just do water changes or use biopellets reactor? And do i need to add food to keep bacteria colony alive?

It's a great question. One no longer has live rock after 'drying out' as it would then be dead rock and all which will follow during the curing process. Are you doing so in a vat or DT?

You asked about food for bacteria. Actually, it would be good to boost the bacteria and then create a fishless cycle with the fantom feed you wrote about.
 
One reason, and I believe the main reason, is that at the end of the cycle you should have 0 ammonia and phosphates, and measurable nitrates.

The nitrates can be high.

A water change is an effective way to reduce the nitrates.

Agreed. It's possible for some nitrates to break down but you can still have nitrates higher than you want. The water change is a guaranteed drop in nitrates.
 
It's a great question. One no longer has live rock after 'drying out' as it would then be dead rock and all which will follow during the curing process. Are you doing so in a vat or DT?

You asked about food for bacteria. Actually, it would be good to boost the bacteria and then create a fishless cycle with the fantom feed you wrote about.

In brute cans with powerheads and heaters
 
In brute cans with powerheads and heaters

Looking back to your first post in this thread, I assumed you were cycling your rocks in the DT. If in Brutes, you don't need to do water changes, you can let the nitrates build up indefinitely. To make the bacterial colony robust, you have to keep feeding it, whether you have live fish in there, or dead shrimp, or ammonium chloride. Your rocks are cured and ready to be pulled out, drained and placed in the DT when your ammonia and nitrite levels in the Brute water remain steady at 0 despite ongoing bacterial feeding.
 
Ok thanks

It had been a few weeks since i last added a tiny pinch of food. I did again just yesterday.

One of my cans actually got a small puncture crack and leaked out about 5 gallons of water on my basement floor. Guess i maybe packed the rocks in too tight.

I'll test again in a couple days. Post a pic of my rock too
 
How long is a cycle 'good' for? If you finish your initial cycle, but don't have fish or CuC to introduce, how long does the tank stay viable?
 

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