# Use dead fish to facilitate cycle?



## Josh (Mar 12, 2011)

I bought two mollies last night because they were on sale 50 cent a piece to help start my cycle on a new tank. One went belly up this morning and the other died just a moment ago. I have dechlorinated the tank and treated it with some bacteria booster. Temp was at 77, which is what I keep my other tropical tank at.

First question is was it just the shock of a new tank that killed them? Its a 30 gal tank so i didn't think ammonia would build up fast enough with 2 mollies to kill them that soon. It may be of interest to note that I got them from pet smart, however the tanks were clean and they looked healthy. I will test ammonia levels when I return home.

Second question, while its never good to lose fish could I keep them in there and let them decay, releasing ammonia to get the tank cycled. Or should I take them out and use another way. My only concern is that they'll leave behind something harmful other than ammonia.

Any help is appreciated, thanks.


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## fishman81 (Jan 12, 2011)

not sure on this one, but i've heard of people using chunks of shrimp from the grocery store as a "fishless" cycle, although it's not truly "fishless" in my mind. Not that i am judgemental about using fish to cycle, i've never done a fishless cyle, but the concept interests me as a scientificly minded person.


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## Josh (Mar 12, 2011)

I think I decided against using the dead fish. Forgot how quickly rotting fish starts to stink.

Tested my water when I got home. Ammonia was at .25 ppm and nitrites were still at 0.


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## automatic-hydromatic (Oct 18, 2010)

I'm not sure if I'd leave 1 entire Molly in the tank, but maybe 1/2 or 1/4 of one depending on how big they are. But I definitely wouldn't leave them BOTH in there.

If it's too much decaying fish, then yeah the ammonia will probably spiral out of control and the smell will be horrendous.

But, this also depends on why they died in the first place. If it was because of a parasite or something, then no way would I leave the dead infected fish in the tank. But if it was just from PH shock then there should be no harm.

If it came from a chain store like Petco, well, I've had about a 25% living success rate with fish bought from pet stores like that... I've had Guppies to belly up over night, but at the same time I've still got a Dwarf Gourami, a school of Blue Danios, and some Cherry Barbs are are doing fine that I got from there.



But honestly were it me, I'd just get rid of the dead fish and try again with another pair of Mollies.

How are you acclimating them to the tank? Just floating them and then dumping them in? Or are you using the complete drip method?


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## Josh (Mar 12, 2011)

I just floated them for an hour. Didn't do the drip method. I've never in fact tried the drip method. I actually ran back by pet smart and gave them the dead fish. They replaced them with two giant danio free of charge. I figure danios are bit more hardy than mollies.

I floated them the same way and let them out. At first they hovered around the top gulping for air which made me a little worried. I knew it wasn't the ammonia or an aeration issue(I have an 18" air stone powered by a 50 gallon rated pump). 

Fortunately they look to be doing better now. They're playing around in the bubbles exploring their new environment. Here's hoping I have more luck with these guys.


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## fishman81 (Jan 12, 2011)

i like petsmart for their return policy, my other local lfs (we only have petsmart and another local mom and pop shop) doesn't do returns... they have high end equip. and some exotic fish but don't do returns on dead fish


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## Josh (Mar 12, 2011)

I absolutely love my lfs(Aquatic Critter - Aquatic Critter Freshwater, Saltwater, Reef Fish & Reptiles ). They have a pretty wide and varied selection. If you can't find it their, they will order it. Very pristine tanks and some of the most knowledgeable people I've met.

Only problem is they're an hour drive away, so I do my little purchases at petsmart.


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## Dean715 (Feb 3, 2011)

If it were me I would take the dead fish back, trade them in on 3 or 4 bunches of anacharis, do a 25% water change and put the anacharis in with some fertilizer at the recommended dosage, I use Flora Pride but there are others, add a couple mollies if its mollies you want to keep, or in a thirty gallon I think three molly size fish would be fine. Do 25% water changes at least once a week, I do them twice a week but once may be enough. If your anacharis stays green and growing your tank will cycle without any bad ammonia or nitrite spikes. Ive cycled two tanks this way and am in the process of setting up another. It takes longer but you can start with and keep the fish you want right from the beginning.


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## jrman83 (Jul 9, 2010)

You really should learn to drip acclimate the fish. Your mortality rate will greatly improve if you do.


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## verdifer (Sep 8, 2010)

I wouldn't use them in the tank for the cycle, you can use Prawns I beleive you folks in the USA call them shrimp.


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## Josh (Mar 12, 2011)

Just did a 25% water change using some API Stress Coat +. I'll give it a few hours and see how they're doing. 

I'm a bit hesitant to put any live plants in because I'm planning on stocking it with a few small breed african cichlids and I heard they love shredding foliage.


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