Water changes/skimming during cycling

[1journeyman]

All right, dang it, this question has come up a lot. I was getting worried about being in the minority on this one (as I'm still learning and I didn't want to be giving bad advice) so I emailed Dr. Fenner. Here is my email, along with how he spliced in his responses (emphasis in bold by me for those who don't want to read it all):Me: Hello there,
Dr. Fenner: Greetings
Me: Your webpage has been invaluable in the past. I'm a huge fan of your books
as well. You all are an awesome resource for us hobbyists.
Dr. Fenner: Ah, welcome
Me: I've got a question about tank cycling that I couldn't find on your website
anywhere else. I am an active part of a discussion group on another website
(where some of us hold "A Conscientious Marine Aquarist" akin to the Bible).
Dr. Fenner: Mmmm
Me: Now, here is my question: Should you run a protein skimmer and do partial water
changes during your new tank's cycle (using live rock to cycle the tank)?
Dr. Fenner: I definitely would... in almost all cases/circumstances, yes
Me: The majority of posters say "No" it will only prolong your cycle
Dr. Fenner: Mmm, not doing so might kill off most all your "life" on the LR...
precluding cycling period... Think about this... there is a need for some
constancy that the water changes, skimming can best provide, along with
checking pH/alkalinity, possibly boosting biomineral content
Me: I disagree. I'm of the opinion that ammonia should be kept in check during a cycle
Dr. Fenner: Yes... we are in confluence here... more than about a (one) ppm becomes
too toxic
Me: The higher the ammonia, the more critters that die on your live rock. Uncured
live rock is going to produce ammonia, but is their a reason to let that
ammonia go off the chart?
Dr. Fenner: Agreed
Me: Am I mistaken? Does ammonia fixing bacteria grow faster in higher levels of
ammonia?
Dr. Fenner: Mmm, only up to a "certain extent"... under unfavorable conditions, including
too high concentration of ammonia, their metabolic rate is depressed, they're
killed
Me: Or is the limiting factor in ammonia fixing bacteria reproduction rate?
Dr. Fenner: Only at less than ideal/toxic conditions
Me: Looking forward to your answer either way. I would love to be right, but I'm
more interested in doing things the right way.
Dr. Fenner: Good... we are also similar in this regard
Me: Also, may I copy your response and post it, in its entirety?
Dr. Fenner: You are welcome to re-state anything from me. Cheers, Bob Fenner

 

[jdragunas]

I agree. I ran my wet/dry filter during cycling.
Ok this applies for wet/dry filters only: If you don't run your filter during the ammonia spike, wont' it just take longer for the ammonia fixing bacteria to grow on your filter media (bio-balls)??? If you run the filter during cycling, it causes that bacteria to grow everywhere, not just in the tank. This is a good thing, right?
Also, i've heard many times that you shouldn't do water changes during cycling. If you don't do water changes, how will your nitrates ever go down??? Just curious.
jenn

 

[1journeyman]

I believe a lot of people do a big water change when the cycle is over to help get rid of nitrates.

 

[acekjd83]

keep in mind that skimming and filtering are totally different. a wet/dry filter is designed to promote bacterial proliferation and waste metabolism by maximing exposed surface area and dissolved oxygen content. protein skimming physically removes the wastes themselves, completely precluding bacterial breakdown of the wastes, effectively limiting the amount of food available to the bacteria struggling to become established. by all means, biological filtration media should be employed during the cycle, but protein skimming and activated carbon should be left out of the cycle, imho, as these types of filtration are completely non-biological, and compete with the bacteria that you are trying to establish.
this is of course, stated with the caveat that you have added a "reasonable" source of ammonia. it is not uncommon for people to throw a bag of frozen shrimp in their tank to "speed up the cycle", raising the ammonia content to roughly that of a bottle of Lysol, when all you need is a single small shrimp, or a bit of food; if you can smell your fish tank from across the room, you might have a bit of a problem. in this case, drastic action is needed to keep the tank (and your room) habitable, including water changes, removal of the ammonia source, protein skimming and activated carbon. there is no way to "speed up" the nitrogen cycle other than starting with highly populated substrates.
i believe that Dr. Fenner would agree with me in this regard, and i appreciate his expert input!

 

[1journeyman]

Well, in this instance, we were talking about cycling a tank with uncured live rock (as stated at the beginning of my email).
I can't imagine your skimmer would get much if you had it runnning while cycling with a dead shrimp.

 

[acekjd83]

thats the idea... a small source of nitrogen will not overload your new biological filter, so there should be no need for a protein skimmer.

if you have only a small amount of nitrogen being released, ANY skimming will remove much of that small amount of nitrites and nitrates.

 

[1journeyman]

I think I'm confused...
The point of skimming during curing live rock is to remove much of the "junk" from the tank that otherwise would send your ammonia halfway into orbit.

 

[acekjd83]

well, the lr should be washed before being placed in the tank (if it isnt cured) to remove the junk... i personally wouldnt want to just throw an uncured rock covered with crap and dead stuff into my tank. just a good saltwater dunk and rinse will remove most of the stuff that you wouldnt want in your tank without harming the good microfauna in the rock. the rock "curing" is just the nitrogen cycle establishing a healthy bacterial poulation in the rock. you wouldnt use dirty water to fill your tank, so why use dirty rock? the washing obviously wont remove ALL the junk, just most of it, so you'll still have an ammonia source, and hopefully at an acceptable level.