• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Species for Tank Cycling

Tonight Mathew............. I am eventually gonna post here :smile:

Yeah, I didn’t touch it before because it doesn’t have a easy answer. I have always used fish to cycle tank and as long as its done gradually i think that no harm comes to them... some of my 'test pilots' are still swimming about happily breeding in my big FW tank and these mollies have been to marine water and back at least twice.

So, to sum up my feelings... as long as a tank is stocked really slowly no harm comes to the fish in a fish cycle. Last year I cycled 600 tanks all at once and really only had a handful of deaths which I put down to them being in ill health in the first place at importation.

I disagree that 12 days is never enough time to cycle a tank. That's because the ammonia production should be increased or at least steady to build up a larger amount of bacteria in the filter... several large doses of ammonia or dead prawns or whatever, cause population explosions and then die offs... it really needs the steady supply that fish produce through respiration. It can take months before a tank is stable enough to add a octopus… otherwise when you add it, because it produces so much more waste than a fish of similar mass, you are going to get an ammonia increase that your filter can’t handle and stress the octo. The only way to get round that is to have your tank up and running for a few months with a fish mass similar to the octopus and when you get the octo you remove the fish, therefore the ammonia production is similar and no spikes are formed!

An octopus would be much more at risk in a cycling tank because of its skin! A fish has scales (normally) to protect it. An octopus on the other hand has a skin like the lining of your gut. If you could fold it out it would have an immense surface area meters square! Not like a fish. So this skin would make them more susceptible to poisoning.

Now, since we are talking about not hurting animals, and I believe that is the point of a fishless cycle??? Then let me suggest that using uncured live rock is going to kill way more animals than a fish cycle might. That’s why we call it LIVE rock, it’s crawling with all sorts of life and the vast majority of that dies during curing. So I propose that using live rock is killing much more than a fish cycle ever would!

Also, since I’m at it….

IgoRluse wrote, ‘First the nitrate cycle. Animals produce waste in the form of amonia. The aerobic bacteria (living in the upper layers of sand and everywhere where there is oxygen) bacteria consumes amonia and produces nitrites. A secont type of bacteria (anaerobic living in the deep layers of sand and where there is almost no water circulation) consumes nitrites and produces nitrates. Amonia and nitrites are toxic while most animals can support the presence of nitrates quite well.’

Sort of right, the nitrogen cycle does work from ammonia to nitrite to nitrate but the last part is nitrogen.

The bacteria, which break down ammonia to nitrite, AND the bacteria, which break down nitrite to nitrate, are BOTH aerobic. It’s the bacteria that break down nitrate to nitrogen which are anaerobic and live deep in the live rocks, sand or in a nitrate filter.
Also, ammonia, nitrite AND nitrate are poisonous to aquatic life, its just that they get less toxic as they pass along the nitrogen cycle. Nitrogen, the end result, passes out of the water gradually and is harmless!

One of the reasons that I don’t like DSBs is because the nitrogen can’t properly escape through the water column because a crust forms in the DSB. Then the pollutants build up and build up, eventually the nitrogen cycle collapses in your DSB and goes backwards, just waiting for the day when the whole thing either gets disturbed or finally collapses and the whole thing crashes. DSBs have a shelf life of about 2 – 3 years!

Alright Colin

So im fascinated with your comments regardin DSB's. Since your dislike due to their shelf life, so to speak, what do you think of as a better option?

I suppose you can prolong its life by stirrin it up occasionally????

Im currentley designin me sump (well lookin at it!!! :shock: ), well its in the air at the mo really as im tryin to get chartered an have my interview in a couple of weeks, and the cost of the tank keeps growin an growin!!!!

Nice one fella

Scouse :wink:

Yeah, it’s the shelf life I don’t like and I also see a lot of snobbery about the newest fads… basically rubbishing anything that has come before! The methods I use are tried and tested beyond all doubt… wet/drys and external filters with good skimmers are the best way to go for an octopus tank.

Yes, a DSB does give good results for the first few months/years in a reef tank but its uses are limited with cephs.

I also like refugiums but they are not to be confused with DSBs some people mix them up.

If you stir up a DSB you’ll knacker it as you’ll make the anaerobic conditions aerobic again and that wont break down nitrate... so your DSB just sits there, like an aquatic time bomb… waiting…… to …… go!
Received a frantic call from a local store one saturday morning about a problem with their tanks...you pegged it Colin...the time bomb went off !!! I saw 1500 gallons of salt tanks "crash" in the space of two hours...quite ugly.
Moral: slow and steady wins the race.

Nice one Colin an Greg

Im runnin out of time an need to go so I'll give this some thought an come back on it.



Actually you may as well call me Rich since Steve asked me name earlier. Oh No!!!! Im no longer incognito!!!!! :smile:

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