# Upgrading to Larger Aquarium - Mistakes I Made?



## gillart (Mar 27, 2018)

Hello. This is my first post on this forum. Just wanted to share my experience of upgrading from a 55G cichlid tank to a 125G cichlid tank.

I drained about half of the water from my 55G into a new large garbage can and discarded the rest of the water. 
I put most of the decorations and gravel into the garbage can.
I added a heater and bubbles to the garbage can.
I added all 15 of my cichlids to the garbage can. 
I replaced the 55G with a 125G. 
I filled 2/3 of the new aquarium with treated tap water, then added all of the gravel from my old tank. 
I got the temp right via 3 heaters and then pulled the decorations out of the garbage can and added to the new aquarium. 
I then added all of the water from the garbage can - and the 15 cichlids - back into the tank. They had spent about 3 hours in the garbage can. 
I restarted the Fluval 406 and 106 that I had running and well established from my old aquarium - I didn't clean them for obvious reasons. 
I added a new Fluval FX6 in addition to the 406 and 106. 
Everyone seemed happy. About 2 weeks later things were clouding up so I did my first cleaning - a 50% water change. 
I still did not clean any of the 3 Fluval filters. 
Within a few days many of my fish were just sitting on the substrate barely moving. A few days later 12 of the 15 were dead. 
Only my XL Jack Dempsey, medium peacock, and medium Frontosa survived. 
All 3 are now eating again about a week after cleaning and seem to be happy again. I bought 3 snow whites and added them a few days ago and they seem happy. 
So I have only 6 fish in my 125 right now - afraid to add more, as I assume the tank RE-cycles??

I think I know what I did wrong, but what are your first impressions about why I had this disaster?

Thanks.


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## mambee (Apr 13, 2003)

You should have been ok with using the old gravel and filters. How long were the canister filters unplugged and not running? Maybe the good bacteria in the filterd died from lack of oxygen? Same with the gravel. Maybe the good bacteria were on the surface and died when the gravel was disturbed. In retrospect, you should have tested the water for ammonia, nitrite and nitrate. However, you should have been ok just with using the old filters.


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## wryan (Dec 6, 2015)

Sorry for your loss ...

You clean the old gravel before you added it to the new tank ?

What about any new gravel/substrate that you added ?

The beneficial bacteria that handle the ammonia cycle are surface dwelling ... so it's pretty likely that your old tank had a lot of bacteria on it's surfaces that your new tank didn't.

You do any testing of the water before/during/after this disaster ?


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## gillart (Mar 27, 2018)

I also thought I would be ok with the old gravel and filters. Canister filters were unplugged about 3-4 hours. I had read that I should keep them running or off as short as possible but I forgot to. 
I didn't clean the gravel during the transition. 
I tested the water after the first 2 fish deaths and they said it was a little high in Nitrites but nothing glaring. 
Thanks for replies.


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## Cyphro (Mar 23, 2018)

Since you had clouding your cycle did not come along to the tank which could be fore many reasons.

If I move a whole tank like that or think it's not cycled then I don't feed anyone for the first week, and only slowly start feeding again to get back to normal levels. This won't work with all fish but for cichlids it's usually no big deal.

So you did not really make any real mistake, but when you saw the clouding would be the time to do a bunch of water changes, water testing and so on.


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## nodima (Oct 3, 2002)

That is a tough scenario, as on the surface you did everything correctly.

Hard to say what the cause was - the couple of hours the filters were not running is not long enough to kill of the BB, IME. This assumes the filters were not thrown outside in freezing weather or something weird like that.

There should have been enough BB in the filters and substrate to not have the tank re-cycle. Is it possible that there was a lot of detritus in the gravel which was brought into suspension and overloaded the BB? Thinking that if it was in the gravel sort of locked away in the 55, perhaps it was too much to be exposed in the 125?

Lot to speculate on, but I don't see where you did something obvious that would have caused this.


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## The Morning (Nov 22, 2017)

Just a thought. How are the spray bars angled on the filters. Are any of them breaking the surface or are they all angled down? Might be a lack of oxygen issue if there is not enough surface agitation.


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## noddy (Nov 20, 2006)

It sounds like you did everything right. The first thing that pops into my head is whether you used water conditioner when you did the first w/c after the move.


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## punman (Oct 24, 2003)

Sounds like you planned it out pretty well.
I try to not have media out of the filter and not operating for more than 30 min. Really paranoid about that. 
I would have dumped the media into the large garbage can (not to protect the fish but to protect the media).
I would have also run a hang-on-back filter if I had one, with some established media, put on the garbage can to protect the fish and the media.

I had to do a change in the fall when we re-carpeted the whole basement. Two 90 gallon tanks had to come out of one room and be put in another room for 36 hours, then emptied and put back. So a double switch! I lost no fish and we are talking Tanganyikan cichlids, not hardy goldfish, and only kept 10% of the original water. Reason I feel I was successful was that I had a spare 20 gallon tank that I could use for running filters and temporarily housing fish.


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## smitty (May 7, 2004)

If you added that water to the substrate and plants without any of the old water. I believe you destroyed much of that good bacteria. Whatever was left could not handle a tank double the size, and the imbalance caused the problems. Whenever I have don anything similar to what you have done. I put the gravel and cycled system in the new tank first, and turn on my pumps so keep everything circulating. Then I slowly add the water, about 15 gallons every 30-60 minutes. It has worked to a charm, and I think I may have a video of the steps I take. Adding all that water at one time has caused be problems also. Don't beat yourself up because you learned something and thanks for sharing.


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## punman (Oct 24, 2003)

Does the old water really hold all that much bacteria? See my post above where I have done new setups with only 10% old water. Protecting the media, I believe is the real key.


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## Cyphro (Mar 23, 2018)

The old water, no. Should probably not send that over. Personally I would just scrub the whole gravel too except a small portion then move that first, and only put the fish and filters over directly from the old tank. That might be hard if it's going in the same spot though.


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## fish_gazer (Nov 9, 2017)

Sorry to hear that. Thanks for sharing.


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