Figure 8 Puffers Dying

[myenigmaself]

In the past two days I've had two of my figure eight puffers die for no apparent reason.

Water Parameters:
SG: 1.003 (one hydrometer read 1.003, one read 1.004)
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: <5ppm
pH: 8.2
Temperature: 77

Tanks
Main Tank:
6 (now 4 ) figure 8 puffers
16 bumblebee gobys
sand substrate (average about 1/2" deep)
some anacharis
1 large water sprite
1 medium anubias
bricks
Tons of hiding places

Sump:
3 mollys
6 ghost shrimp
some pond snails I've been raising in the sump
1 water sprite
a bunch of anacharis
a rock covered with java moss
a few small java fern plants
gravel substrate
crushed coral as filter medium/surface area in overflow chamber

Both puffers had minor fin nipping (not nearly as bad as when I got them) that I believe happened postmortem. They were both eating just fine. I've been feeding them primarily frozen large krill, blood worms, and mysis shrimp. They also occasionally get live ghost shrimp and snails from the sump as treats. Everybody had plump bellies (there were some sunken bellies when I got them, but they'd filled out just fine).

Tank history:
The tanks have been setup for almost two months. Added ghost shrimp almost two months ago. Added the mollies over a month ago. I've had the puffers for three weeks now. I added the gobys about a week ago.

I did treat the tanks with melafix for 4 days when I got the puffers to help with nipped fins. Nothing in over 2 weeks now though, and I've done probably 75% in water changes in total in that period (I do 10% water changes every couple days when I clean up detritus).

I've had a few ghost shrimp pass on naturally. I also had one molly pass away a couple weeks ago, but I know that was due to bullying from the other mollies. Other than that everyone's been very healthy. I've had no problems with appetite, the mollies, gobys, and puffers all eat until they have full bellies. I feed twice a day, no more than they can eat in 2-4 minutes. Two of the mollies are actually getting a little overweight so I only feed the bottom tank (sump) once a day and they get to eat whatever gets washed into the sump from the main tank.

I know my ph is a little high, I'm assuming that's due to the crushed coral. As that's where most of my surface area comes from I'm reluctant to remove it as the tank may crash. Is the ph too far out of bounds? (I read 7.5-8.0 is the perfect range, and I'm at 8.2)

What else should I be testing for? Hardness? I'm at a loss here. This is my first brackish tank so maybe there's something specific to brackish setups I'm missing. Any ideas?

I'm planning on doing another 20% water change tonight. Beyond that I'm just worrying and playing the waiting game. Any ideas would be appreciated.

Thanks - mk

 

[WILDER]

You would be better off posting this thread in the right section of the forum.
Just copy and paste your thread.
Good Luck.

 

[myenigmaself]

Thanks Wilder! I posted a link to this post over in the oddballs institute too. No casualties in the past couple days and again, everyone seems healthy. Maybe it was just a fluke? Keeping an eye on everything but I don't think this constitutes an emergency anymore. Thanks!

 

[WILDER]

Ok.
Good Luck.

 

[myenigmaself]

Sigh, two more puffers died yesterday My only inkling that anything was wrong was that one of them didn't eat breakfast.

At this point my only thought is that there's some toxin in my bricks. I removed them yesterday evening and did a 25% water change. I'm going to do another 25% water change tonight and another tomorrow.

I'm planning on replacing the bricks with plants. Anacharis and Anubias have been holding up in my tank, but my water sprite hasn't held up so well. I'll try to get some more java moss too, but it's in short supply around here.

Any other ideas or suggestions are more than welcome.

 

[WILDER]

What type of bricks were they. Were they steralised in boiling water before they were added to the tank.
Water changes and add some fresh black carbon.

 

[myenigmaself]

Thanks Wilder,

They were standard red bricks (actually half bricks) made from portland cement. I didn't boil them, but did thoroughly wash them before adding them. That was a great suggestion on the black carbon. I bought a brick sized filter bag of it and added it in with the bags of crushed coral in the sump. I should have thought of that!

No more casualties and as always, everyone seems healthy. Everyone is active and eating well. As my top tank is kind of "naked" right now I think they're stressing out just a little bit since they don't have anywhere to hide nor do they have anywhere to explore. I've added another larger anubias but it gets lost in the big tank. I'm almost ready to order some java fern and java moss, as I've been unable to find any more in the local establishments.

Thanks again for your suggestions.

-mk

 

[WILDER]

Did the fish start to get ill once you added the bricks?

 

[myenigmaself]

Hi Wilder,

Yeah, it was about two weeks after I added the bricks that my little puffers started passing away. Everyone who's survived is still doing well, the puffers are eating well, even eating out of my fingers when I wave some krill for them. The gobys eat like crazy, and my mollys are still fat and happy.

I'm definitely thinking it's the bricks at this point. I'm continuing to do frequent water changes and I'm bumping up the SG to a solid 1.005. I've ordered some more plants (as I had a hard time finding any around here) that should be here next week so hopefully everyone will be ok swimming out in the open until then.

Thanks again!

 

[WILDER]

Ok.
Good Luck.

 

[rabbut]

*assuming the figure 8's are brakish*, the salinity is too low. You usually target 1.006-1.011 SG for brackish, so bring it up slowly

 

[DarkEntity]

*assuming the figure 8's are brakish*, the salinity is too low. You usually target 1.006-1.011 SG for brackish, so bring it up slowly

1.003 - 1.006 is perfectly fine for T Biocellatus, 1.011 is a tad high

 

[rabbut]

I'll stand corrected. I assumed they would want the usual brackish water region if they were a brackish species

 

[saz326]

No chance that these fish have become territorial or started to mature and want to kill all males?

Apologies for the "stab in the dark" but I have seen this so many times that I had to offer it up.

 

[myenigmaself]

Thanks for the responses guys. Everything I've ready has stated that a sg of 1.003-1.006 is just fine for these guys, so that's the range I'm sticking with. Above 1.005 and I'm afraid my plants will start to die so I don't think I'll be going any higher than that.

As for territorial issues, I noticed some aggression for the first 2-3 days after the puffers were introduced into the tank. Once everything was settled, however, everyone seemed to be getting along swimmingly. Like I said, the only indication of external injury was some very minor fin nipping that seemed to happen post-mortem (and was much less severe than the nipping they had when I bought them). Territorial disputes are a possible cause of this, but I don't think it's the most probable.

Everyone else has hung on the past few days. One of the remaining two puffers I've seen occasionally itching himself against the terracotta pots. He seems fine besides that, but it's concerning.

Thanks again for your advice and suggestions.