First real tank crash, theories presented (New tank syndrome); What do you think?

[Bgolfer88]

I have a discus tank, or what used to be a discus tank. It is a 28 gal bowfront. I run a bare bottom. In the tank is a 8" x 8" x 3" piece of driftwood. Placed in and around of the driftwood are a few sword plants, as well as 4-5 other small plants. I run an eheim 2217 canister, 2 Topfin 10 HOB filters, and 1 Whisper 20 in tank filter (this filter is fully submerged with filter fiber as media). In my canister I have a course pad, prefilter clay rings, medium pad, filter fiber, a fine pad, one box worth of biomax, and another fine filter pad layered bottom to top respectively. I also have a Whisper 40 air pump with 12" air stone and 2 heaters that keep temp around 84 degrees.

Water parameters as of 5-6 days ago:
pH: 6.6
NH3: 0
NO2: 0
NO3: 5

Water parameters as of today:
pH: 6.6
NH3: .5
NO2: 0
NO3: 0

So it would certainly seem as if I restarted my cycle somehow. During the last 5-6 days (when I personally last tested my water) I have done a couple 75% water changes. I have a bare bottom so I always make sure to get everything off the bottom. I feed fish in smaller amounts several times a day.
Stocked in the tank I had 2 adults on the stunted side and one juvenile 2" long.
I moved one of the adults to a friends house for breeding purposes night before last. When I did I drained some water out into the transport bucket. This lowered the water level below the point that the two Topfin 10 HOB scould operate so I switched them off.
This is where I feel I may have made an error. I had a packed schedule yesterday and didn't end up toping off the tank enough to where I could turn the HOB filters on again. The other filters and air stone were still running.
When I woke up this morning the little discus was dead. I did tests but really didn't even think to check the ammonia, cocky on my part. I found out at my LFS when I went for hardness test specifically, and anything else they wanted to test.
When I got back my remaining discus was showing signs of ammonia poisoning. He is in an alternate tank now and is doing better but doesn't look out of the woods yet (I checked the ammonia in that tank before adding!).


So I have a few theories:

1) I usually keep up very frequent water changes every 2-3 days of at least 50% usually 60-70%. I already had very low nitrates indicating not much NH3 to go thru the nitrogen cycle in the first place. The last time I serviced my canister filter was approx 4-5 weeks ago and I am worried that I may have damaged my biomedia in the process (I'd rather not explain). So the canister may not have built up the necessary bacteria yet since the process supposively can take up to 6 weeks.
This coupled with an increased demand on the remaining Whisper 20 filter may have caused the ammonia spike. Due to my low nitrates I probably should have thinned my plants while ago. They had some, although not alot, of dying leaves that may have caused NH3 to rise quicker.

2) I changed my water too much. In theory if I do too many water changes and keep the water 'too clean' there may not be enough acculation or even presence of the necessary elements to keep the nitrogen cycle going and the system crashed.

3) Although I've had alot of success with canister filters, I may have too much faith in them to run even a 28 bowfront along with a Whisper 20. I may have just not had enough circulation even if I had bacterial colonies established in the media.

4) Probably most likely a comination of them previous 3.

Besides moving the fish out of the aquarium I have: topped off aquarium with R/O water usually reserved for my saltwater, restarted HOB filters, pruned plants and added additional biomedia from other tank (that has been historically disease free).

If you agree with any of my theories please let me know. Or if you have any additional theories or advice I'd like to hear from you as well. Thank you for your time!

 

[Mgamer20o0]

how long since you added the discus to the tank?

 

[smitty]

I think you are doing to large a scale of water changes aqt such close intervals. Also when you clean that eheim if you are exposing the filter media to fresh clean water you are killing any and every bacteria in that filter. If you waited 7-10 days to change that much water you probably would not have that problem. If you feel you want to stick with 2-3 days then change 25 pct of the water.

 

[blue2fyre]

I think you are doing to large a scale of water changes aqt such close intervals. Also when you clean that eheim if you are exposing the filter media to fresh clean water you are killing any and every bacteria in that filter. If you waited 7-10 days to change that much water you probably would not have that problem. If you feel you want to stick with 2-3 days then change 25 pct of the water.

I totally disagree. Many discus keepers do daily water changes of up to 90% without any issues. In fact with discus it is often recommended to do more water changes instead of less. As long as your parameters are pretty much matched when doing these water changes, I doubt this is your problem.

Where did your discus come from? Was the tank cycled before you added them? How long has the tank been set up? Discus are pretty sensitive and with all the feeding in a small tank it would be pretty easy for the ammonia to spike IMO.

 

[Bgolfer88]

Its been a discus tank for a few months now. I have check ammonia before, although not for at least a month, and it was always 0. My nitrates have always been 10 or under. The tank itself has been set up for approx 6 months. Regardless, I'm sure it was cycled. I'm about to do another NH3 test to see if it came down at all during the night.

 

[rufioman]

It's not the water changes I believe..some experts agree 90% weekly is the best water change but for touchy fish like discus I have no idea. I have no experience in discus but as a general rule I do water changes every 5-7 days of 50% depending on what my kit says the ammonia levels are at. I used to use advanced test strips, not the crappy aqueon or topfin ones, and have had no problems with a sort of "mini cycle". I moved to the api liquid test kit finally though. Anyways. My pops and I think it's possible that it's the combination of frequency of your water changes and the amount your changing. Discus are touchy and if something goes minutely wrong it can hurt them quite a bit. Thus the reason I have yet to get myself a 125+g discus tank I hope this helps...it's all from personal experience and my dad's discus keeping knowledge..

 

[rufioman]

So I have a few theories:

1) I usually keep up very frequent water changes every 2-3 days of at least 50% usually 60-70%. I already had very low nitrates indicating not much NH3 to go thru the nitrogen cycle in the first place. The last time I serviced my canister filter was approx 4-5 weeks ago and I am worried that I may have damaged my biomedia in the process (I'd rather not explain). So the canister may not have built up the necessary bacteria yet since the process supposively can take up to 6 weeks.
This coupled with an increased demand on the remaining Whisper 20 filter may have caused the ammonia spike. Due to my low nitrates I probably should have thinned my plants while ago. They had some, although not alot, of dying leaves that may have caused NH3 to rise quicker.
Maybe...

2) I changed my water too much. In theory if I do too many water changes and keep the water 'too clean' there may not be enough acculation or even presence of the necessary elements to keep the nitrogen cycle going and the system crashed.
Too much, too often.

3) Although I've had alot of success with canister filters, I may have too much faith in them to run even a 28 bowfront along with a Whisper 20. I may have just not had enough circulation even if I had bacterial colonies established in the media.
Maybe but doubtful because your substrate/decor would still have bacterial colonies on them.

4) Probably most likely a comination of them previous 3.
Yup.

Too many changes in tank dynamics cause crashes/instability :/ Only real thing I can think of.

 

[EmilyMarie85]

Guessing here...

maybe the 2 HOB's were (for whatever reason) more established then the other 2 filters. Given the amount of water changes you do, keeping the water so clean and all, there wouldn't be much chance/need for the other 2 to build colonies up? I mean, BB colonies only build up to handle the bio-load you have -- so if most the BB was in the 2 HOBs and then those were turned off... ? just a guess?

Edit: Makes a little more sense in my head, since I just thought of the tank being bare bottom (having no BB colonies in substrate)

 

[blue2fyre]

Looking back on your other threads you have had trouble with these discus for a while. Seems they have been sick off and on? Usually 3 is not a great number for discus. They needs groups of at least 5 otherwise the other 2 will gang up against the other. They also stress very easily which can lead to death.

I'm not sure if your tank has crashed honestly. The ammonia could be because of one of the discus deaths or the over feeding that discus need. The lack of nitrate is most likely due to the water changes and the plants you have.

 

[Squawkbert]

(I'd rather not explain).

That, and even trying to keep discus in a 28g tank are probably to blame. I suspect that your bacteria took a major hit and that has more or less restarted your cycle.

w/ the majority of them living in your 2217, I have to ask more about what you would rather not explain... was there a power outage of more than a few hours involved?

What I'd do - long term, I'd move all of that filtration & plants to a 72BF (assuming you prefer bow fronts), cycle it thoroughly, then add a couple of severums. 6 months later, get the temp up slowly and replace sevs w/ discus.