New Tank Syndrome after a water change and filter service??

[sfarkhan]

The tank just passed a month today.

Not sure what I did - I've owned fish for a while and I know all the rules for avoiding new tank syndrome.

Saturday - did a 20% water change and serviced the 406 by removing the carbon and swapping out the purigen with fresh bags. I rinsed the sponge and biomax in declorinated fresh warm water and added Seachem Matrix to the basket that previously had carbon.

All day things were well, had St. Patty's day party and left the lights on for the guests - tank looked great, no weird things going on. At 1:30 AM - I went to bed and switched off the lights manually.

Sunday morning I got up at 10 AM and my Koi angel was dead, upside down. Two amano shrimp had gone carpet surfing, one of the last neons and the chinese Hillstream Loach were dead...

I bought that koi at 1/2 it's size and it was a good 6+ inches nose to tail.

The other two angels were fine, the cardinals were up at the top gasping for air and the otos and corys were making trips up to get air...

Quickly started a water change - and tested the water.

pH - 6.4
NH3/4 - 0 free (Seachem)
NO2 - 1ppm
NO3 - 10-20ppm

Nitrite spike? What the...?

Did a 50% water change, restested and NO2 - 0 ppm

Went ziplining all day. Came home around 9 and the fish were distressed but none were dead - Started a water change and tested the water again.

pH - 6.4
NH3/4 - 0 free (Seachem)
NO2 - 0.5 ppm
NO3 - 10 ppm

Changed 50% of the water.

This morning woke up to only the otos going up for gasps.

Tested the water and started a water change.

pH - 6.4
NH3/4 - 0 free (Seachem)
NO2 - under 0.25 ppm
NO3 - 10 ppm

Changed 20% of the water

tested NO2 again - 0 ppm

Headed to the office today. I'll test it when I get home and do another W/C if necessary.

It totally caught me off guard - I used all the precautions on Saturday - Did my usual routine. Only difference was the water used to rinse the filter material was Prime treated warm fresh water.

It wasn't hot, but maybe the warmer water killed the bacteria off?

They were fine all day from the time of water change (noon) to 1:30 AM and nearly dead at 10 AM.

I'm trying to trace my steps and I've looked up New Tank Syndrome (NTS) after water changes online and I did everything right as far as I can tell. I'm weary of how long this will progress and I don't want to do whatever that caused this again.

Sigh

[krisw]

I'm had oddities like this as well when doing both a filter cleaning and water change at the same time. I often try to do filter cleanings independent of water changes now when I can, particularly on new tanks. Otherwise, your symptoms sound very familiar to a CO2 dump in progress, but the pH would have changed once the tank ran out had that been the problem. Worth making sure your tank's still full though.

[Aaron]

I second Kris. Check your CO2 levels.

[sfarkhan]

Thanks guys! I immediately looked at the CO2 when I saw them gasping on Sunday morning. It turned off last night with the lights and it's bubbling at 1-1.2 bps currently.

I'll make a mental note not to change water and filter media on the same day - I didn't think about that.

[jweis]

I'll make a mental note not to change water and filter media on the same day - I didn't think about that.

I've been there and done that too. I also try not to mess with the filter too much if I do a major trim.

When I peform filter maintenance I only change the floss if it is falling apart disgusting. Otherwise I just pour some old tank water over the media and clean out any gunk build up on the mechanical parts. I found if I do much more, then I have shrimp deaths.

[sfarkhan]

Looking back the only thing I did differently was use warmer tap water treated with Prime to rinse the old filter contents and the new matrix. In the past I always do it with dirty tank water.

It's my first time reopening the 406 since I set it up so I was thorough to make sure I didn't miss anything. I may have over rinsed it.

at 8:30AM the cardinals were all breathing air again. the otos and corys making trips up to do the same.

I tested the water -

pH 6.5 (tested twice)
KH 3
NH3/4 0 free (seachem) (tested twice)
NO2 0 (tested twice)
NO3 10

I checked the CO2 and it's a steady 1-1.5 bps

There is a visible film on the surface of the water - I have changed the water daily which causes it to disappear and then reappears later the same day. Could the Matrix have something to do with this? Other than the filter - I haven't changed or added anything.

Water change time.

[Aaron]

I've been thinking about this some more. How densely planted is your tank? The denser the better. Often people advocate so called "fast growers" to soak up excess nutrients during the break-in period.

[sfarkhan]

It's getting denser as there's new growth. I'll take a pic in a few minutes and post day 1 vs current day 31.

Since my last post the daily water tests have been consistently:
pH 6.6
KH 4
NH3/4 0
NO2 0
NO3 ~10-15

I dropped the CO2 injection to 1-1.5bps and today I dropped it to 1bps.
The lights come on in stages - 1 bank 5000k, then both 5000k/6500k an hour later. The 6500K shuts down about 8 hours later and the 5000k shut off an hour after those. I changed the time of the CO2 to come on only when both banks of lights are on - 8 hours.
I tried putting the lily output at water level to churn the surface film and pull some O2 into the tank. I have reduced feeding.

a couple of observations:
*The otos and corys are coming up for air every 10 minutes in the morning till both banks of lights come on.
*There is an algae bloom - not crazy, but some hair/string algae - I expect this in the first month. I haven't started adding macro ferts - not sure which method and I wanted the tank to stabilize before I add more stuff. I am dosing micros (Seachem Flourish) every 3 days.
*I am doing a pH/KH calculation with 1bps it's dangerously close to 30mg/liter. The inline diffuser may be too efficient?


Kris mentioned that I could be gassing the fish - I didn't think the CO2 was high enough to kill the fish at 1.5bps. But the combination of nitrites which suffocate and CO2 may have been what killed the fish that are CO2 sensitive. I think the surface film also reduced the CO2/O2 exchange which exacerbated the issue.

The fish may have been able to tolerate one or the other but not both...

Ugh, I feel stupid

I am going to move the lily pipe to the water surface and see how the chemistry settles and how the fish react. I may also need to get a pH sensor - the drop checker is green but I may need to assess what the proper shade of "green" is and be able to act.

[sfarkhan]

Images day 1 vs today. I think this is pretty decent growth, no?

I had purchased 4 Apistos last week before the die off this weekend. The water was stable on Monday when they arrived and seem to be doing well.

Day 1

Day 1

Tank_day_1.jpg (179.04 KiB) Viewed 3382 times

Day 31

Day 31

Tank_day_31.jpg (239.62 KiB) Viewed 3382 times

[scientist0724]

I like how my nyphaea is filling in in your tank

Arlene