PDA

View Full Version : Effects of Water changes during cycling


Mythicalelf
03/05/2015, 09:07 AM
From what I have read about water changes, the pros and the cons, I know I will do them in the future.

My question now is will it mess with my cycling of the tank? speed up, slow down, no change

alexander_ktn
03/05/2015, 09:15 AM
Some say it will slow down the cycle, but in my opinion as long as you don't do 100% changes all the time it will not have any appreciable effect on the cycle and can be a good time to test your routines.

There are so many variables in the duration of a cycle (with how many bacteria you started out, what the live rock is like, what you fed your tank with, etc.) that a water change won't really matter imo.

I also like to use a skimmer in that time and run a normal lighting schedule, all things that might or might not make it take longer or promote algae. I really like to set up the system and run it like it would normally.

FraggledRock
03/05/2015, 09:23 AM
From what I have read about water changes, the pros and the cons, I know I will do them in the future.

My question now is will it mess with my cycling of the tank? speed up, slow down, no change

http://reefkeeping.com/issues/2005-10/rhf/

worth the read.

A sea K
03/05/2015, 09:25 AM
I feel no water changes while cycling a tank is best, IMO it can only slow things down and offers no benefit. Just feel there is not much sense in removing ammonia (needed to establish bacteria) or any beneficial bacteria already established.

FraggledRock
03/05/2015, 09:28 AM
I feel no water changes while cycling a tank is best, IMO it can only slow things down and offers no benefit. Just feel there is not much sense in removing ammonia (needed to establish bacteria) or any beneficial bacteria already established.

http://reefkeeping.com/issues/2005-10/rhf/

A sea K
03/05/2015, 12:15 PM
http://reefkeeping.com/issues/2005-10/rhf/

OK, a worthwhile article but where does it address water changes and its relationship to the nitrogen cycle?

FraggledRock
03/05/2015, 12:23 PM
OK, a worthwhile article but where does it address water changes and its relationship to the nitrogen cycle?

sorry wrong link but still applicable

this is the one i wanted:
http://reefkeeping.com/issues/2009-04/newbie/index.php

A sea K
03/05/2015, 12:29 PM
Very interesting, you learn something new everyday. I guess if you have off the chart ammonia levels and your curing LR during the cycle I can see some merit.
I'll just stick to my routine and cycle without w/c.

FraggledRock
03/05/2015, 12:32 PM
Very interesting, you learn something new everyday. I guess if you have off the chart ammonia levels and your curing LR during the cycle I can see some merit.
I'll just stick to my routine and cycle without w/c.

of course I wasn't trying to convince you to change what you find works for you, it is good to bounce ideas off people.

I don't see it worthwhile doing water changes in a new setup either unless there is an emergency situation to get under control, like what I am going through, tank crashed last week and have to keep some inverts alive after all my fish died and most corals...

A sea K
03/05/2015, 01:08 PM
So then lets re-visit the situation,
If you are cycling a new tank with dry rock and are trying to establish and maintain ammonia levels(fishless/ammonia dosing/ghost feeding) then I say no w/c.
On the other hand if you are cycling with fish and or LR (curing) and you need to control out of hand/toxic ammonia levels then I would say yes w/c.

There, that should work. I am now a student of both methods.

skeeter_ca
03/05/2015, 01:28 PM
So then lets re-visit the situation,
If you are cycling a new tank with dry rock and are trying to establish and maintain ammonia levels(fishless/ammonia dosing/ghost feeding) then I say no w/c.
On the other hand if you are cycling with fish and or LR (curing) and you need to control out of hand/toxic ammonia levels then I would say yes w/c.

There, that should work. I am now a student of both methods.

That seems like the best advice to go by.

When I bought live rock from TampaBaySaltwater their instructions are to monitor ammonia levels and when they get to 1.0ppm or higher start doing water changes to keep ammonia below 1.0ppm. Their reasoning is to help any live organisms still on the rocks to stay alive and not be killed off by the very high ammonia levels created during the cycling without water changes. Worked for me. They amount of living creatures on the rock after the cycle was amazing.

Hitch08
03/05/2015, 01:50 PM
Wow! 25% water change per day! I'm going to need to buy more salt.

Azedenkae
03/05/2015, 02:21 PM
Water changes will prolong the cycle. :) Whether it is by an amount that has a large or small effect will depend on each individual situation.

Basically imagine that every time you do a water change, you are shifting concentrations of everything towards the state of 'normal' saltwater. This is of course why certain things decrease (like waste) and stuff. If you have high ammonia and stuff, a water change would lower that. In general that is good, but not in the context of the initial cycle.

See, we want to grow and propagate microbes, right? And they require sustenance. Doing water changes will lower the amount of nutrition in the water, and the amount lowered could have a significant effect by not allowing as much food to be consumed by the microbes, hence slower growth and stuff.

Doing a water change at this point is like adding food into the tank for your fish, and then removing a portion of it out... which is only ever good if you added excess food, pointless in all other cases. Same here, doing a water change doesn't mean you'd stop the cycle, but you are just unnecessarily potentially prolonging it.

[EDIT]

Of course, unless you are cycling with fish - which is bad anyways, not because the fish could die (well it is bad), but because to keep the fish alive especially when cycling a tank using dry stuff, you won't be able to really push the microbial load to the limits.

On the other hand if you use live rock, then in fact it probably won't matter, but at the same time you may not even be experiencing a cycle anyways. XD

alexander_ktn
03/05/2015, 03:03 PM
This really assumes that the bacteria will reproduce at a much slower rate at e.g. 0.2 mg/l ammonia than they would at 0.3 or 0.4 when in fact they probably won't.

Same thing happens at the end of the cycle: so now you have zero ammonia and zero nitrite, that means all was for nothing and the bacteria die from starvation? It won't happen because once you are over some critical mass the reproduction and adaptation to new levels becomes very fast.

Cincyreef
03/05/2015, 04:09 PM
I just cycled my 29 biocube with live rock. The nitrites finally dropped to 0 yesterday. They were high since Feb. 3rd! If I had to do it all over again I wouldn't change water, as most stuff died off the rock anyway with the high ammonia. I changed 10 gallons first two weeks, then changed 5 gallons, about a week later. All in all it took exactly 6 weeks to cycle using 45lbs of live rock.

Mythicalelf
03/05/2015, 04:15 PM
Thanks for the input, I think I'm just going to hold off on the WC at least till cycle is over then start my normal water change routine.

alexander_ktn
03/05/2015, 04:46 PM
If I had to do it all over again I wouldn't change water, as most stuff died off the rock anyway with the high ammonia.

Yeah makes total sense that if you had problems with high ammonia not changing the water would have helped...

m0nkie
03/05/2015, 04:52 PM
the only time I was recommended to change water during cycle was dosing too much ammonia. I usually start the cycle by dosing Dr. Tim's One and Only. basically bacteria in a bottle + adding some pure ammonia. Too high concentration of ammonia slows the bacteria process. That's why Dr. Tim recommend a water change if your ammonia is too high.. it may "stall" your cycle..

I've seen ammonia at 6+ppm during cycle.. took an extra few weeks but it still cycled..

Azedenkae
03/05/2015, 05:55 PM
This really assumes that the bacteria will reproduce at a much slower rate at e.g. 0.2 mg/l ammonia than they would at 0.3 or 0.4 when in fact they probably won't.

Same thing happens at the end of the cycle: so now you have zero ammonia and zero nitrite, that means all was for nothing and the bacteria die from starvation? It won't happen because once you are over some critical mass the reproduction and adaptation to new levels becomes very fast.

No it only assumes that bacteria will grow slower, doesn't have to be MUCH slower. The question is can a water change slow down the cycle and the simple answer is yes or no.

Of course the bacteria won't die just because parameters are at zero for example. That's like saying our fish would die the moment we don't feed them or the likes. That's crazy. Of course they can go on for a while without further sustenance.

But fact is nutrient concentration do play a part, and lower concentrations can and do have an effect.

This paper for example: http://jb.asm.org/content/107/1/210.full.pdf investigated effect of food concentration on growth. And it is clear at the lower concentrations growth is limited.

Of course at higher concentrations it won't matter. As the answer here would be yes, a water change can slow growth.

alexander_ktn
03/06/2015, 01:22 AM
This paper for example: http://jb.asm.org/content/107/1/210.full.pdf investigated effect of food concentration on growth. And it is clear at the lower concentrations growth is limited.

The first paragraph in that paper reads (emphasis mine):
It is common experience that a bacterial culture, growing in a medium in which one nutrient limits the final crop, grows at a constant specific rate (exponentially) until just before growth ceases from exhaustion of the limiting nutrient. This observation implies that, over a wide range of concentration of nutrient, the specific growth rate is independent of the concentration of nutrient; only after the concentration is greatly reduced does the specific growth rate decrease.

As I said, I do understand the concept of nutrient limitation, but in a cycling tank with live rock and/or added ammonia by whatever means, you will not get to a point where low ammonia limits growth, rather the opposite, since we operate close to toxic ammonia levels there (which would slow growth) most of the time anyway.

nmotz
03/06/2015, 02:30 AM
So then lets re-visit the situation,
If you are cycling a new tank with dry rock and are trying to establish and maintain ammonia levels(fishless/ammonia dosing/ghost feeding) then I say no w/c.
On the other hand if you are cycling with fish and or LR (curing) and you need to control out of hand/toxic ammonia levels then I would say yes w/c.

There, that should work. I am now a student of both methods.

This ^. I'm presently following line 1 of this guidance in cycling my tank with dry rock/pure ammonia.

Azedenkae
03/06/2015, 04:15 AM
The first paragraph in that paper reads (emphasis mine):


As I said, I do understand the concept of nutrient limitation, but in a cycling tank with live rock and/or added ammonia by whatever means, you will not get to a point where low ammonia limits growth, rather the opposite, since we operate close to toxic ammonia levels there (which would slow growth) most of the time anyway.

Did you even attempt to read the entire paper? Or at least the results/discussion?

alexander_ktn
03/06/2015, 04:24 AM
I did, and I acknowledged even before that, that some nutrients might be limiting (hell, I dosed a nitrogen source to get phosphate down in a carbon dosed system) - but the article shows that as long as there is a high enough concentration (and you have that in a cycling tank) the relative amount of nutrient will not increase growth. I.e. if the bacteria are "sated" they will grow at the same level, even if you increase nutrients.

And as far as ammonia is concerned we are way above any limits in a cycling tank - we are often even scraping on the toxic concentration.

So please show me a study that says bacteria involved in the nitrogen cycle (not E. coli) are limited by ammonia concentrations in the neighborhood of 0.1 ppm to 0.5 ppm.