Why did my fish die?!

[K7BMG]

I have to agree with Brandon429.
This was not an Ammonia issue and or cycling issue.
One died right off the other lasted a while as he went to bed with it alive.

They were poisoned by what ever was used in the tanks construction or process.

What materials were used in the tank and sumps construction? (All of them)
Glass, plywood, acrylic, plexiglass, combination.
Were these materials new, or were they taken from something else and reused?
If reused what were they used for previously.
Were the materials extensively cleaned free from all prior potential contaminants.

What adhesives were used? be specific. Take a picture and post them here.
Take a picture of everything and post it here.

Do not add anymore animals until you KNOW what happened.

 

[Foughter]

I'd really like to confirm the sealant used by the OP on this DIY tank before I join the ammonia squad. That could be the issue there. Many types contain mold inhibitors or other chemicals and are not fish safe.

Even if ammonia is a problem at the moment (and it very well may be) we could be treating the symptom and not the source. Especially if it's causing things to die - bacteria potentially included.

That’s it.... now what do I do to resolve the problem?

 

[K7BMG]

I wish I could answer your question.
I have no idea if this can be fixed.

My only thought would be to rebuild it with 100 pure silicone.

 

[Doglips56]

That’s it.... now what do I do to resolve the problem?

Oh my. This is the most likely culprit. I totally missed the part where you said you’d built it yourself. Anything that says Mold Free is a no go. I think there is a GE version of pure silicone if you can find it but you will have to completely tear down the tank and scrape off every last bit of this and give everything a citric acid bath and scrub. So so sorry. Did you by chance ask any experienced reefers for help? They would’ve told you not to use this. I hope this setback doesn’t keep you from having your dream tank we had setbacks too

 

[Dark_Knightt]

Just joined the thread and i know this hasnt much to do with the thread. Im a huge clownfish lover so 1. Im sorry for your loss RIP, and 2. What species were they? Just reg. ocellaris, or designer?