What chemicals kill aside from nitrate nitrite ammonia?

[Meloco14]

I found my pygmy angel dead today without any signs yesterday. He was eating and acting normally. However the last couple days my royal gramma has been weird, hiding a lot more and not eating as much. Ammonia, nitrate, and nitrite are all 0. I did a water change yesterday. The temp is 77, salinity is fine, I don't get it. The calcium level is a little high but I dont think that kills fish, does it? The last time I tested phosphate was probably a week ago and it was 0. I will test it again but I dont think that kills either. I havent introduced anything new to the tank except replaced the heater with a new one and added a new powerhead. My two gobies are acting normal, my shrimp have been out and about, everything else is ok. The angel however had a suspicious looking snail eating it when i found it. I call it suspicious because it resembles a cone, but I'm not sure if it is. anyway I took it out as a precaution, but if that is what killed the angel it doesnt explain the gramma. Any thoughts? tia

 

[kyabk]

Off the top of my head these are things that I would check...Do you do anything to dechlorinate the new water before you add it into your tank when your doing water changes? What about your PH levels? You said you added new pumps and a heater. Its possible that one of those devices could be faughlty in that it is letting a stray electic current in the tank. I have had that before. If it happens it doesn't kill fish fast but slowly puts stress on them. Hope you find the problem.

 

[Meloco14]

Thanks, I checked the pH, it's a little low, at 8.1. The alkalinity is 3.0 meq/l, which is perfect according to the calcium supplement/buffer I use, C-balance. The calcium levels are way high for some reason, at 750mg/L. I don't know why this is, I haven't been dosing calcium for the last month because I didn't have the test for it yet. I wonder if my tap water has high levels of calcium...something to check. Anyway could this kill? And how do I lower the levels? Water change? And how do I get the pH back up to 8.3? I've only seen my gramma once today, and he used to hang out right in front all day. I'm afraid he won't make it much longer. But my gobies and shrimp are happy, or seem to be. I don't get it. And yeah, I dechlorinate water with stress coat usually, sometimes chlor-out. This last time was stress coat. As far as the electricity thing, I just added the new heater and phead yesterday so if it's a slow killer that wouldnt be it. But maybe its the older powerhead. How do I test for this? Test meter? Is it worth getting one of those grounding probes?

 

[Anonymous]

Every chemical will kill at the "right" concentration. For example, if there are too much water (aka, too little salt), some organism may die due to hyposalinity. I know this is useless info for you, but just something to keep in mind all the time.

 

[kyabk]

Well I can't answer all your responding questions since I only have about 2 years expereince myself but here is what I do know. You can increase the PH by using PH adjuster. There are many different flavors of PH buffers/increase/decrease. They are usually a white powder substance. Actually they do sell a perfect PH 8.3. Your fish are looking happy and because they have aclimated to the chemicals in your tank. For example, if a few weeks ago and or months ago your PH was 8.2 or 8.3 as you did small water changes it slowly went down over time and your fish also aclimated to that change. As for how to detect a stray electric current in our tank you can get a volt meter and check that. I bought one for $20 at walmart. I have also heard in other posts from reef.org that many people have found out about a stray current when they had a cut on his hand and actually felt the current when he put his hand in the tank. I have never seen that but I guess its possible. If all fails and everything keeps dying in your tank then you could have a disease in your tank. Question is which one. I have had bad cases of Ick in my tank that killed everything. I have found that doing hyposalinity in the tank will kill parasitic conditions such as Marine "Ich" Check out this link maybe it will help.
http://www.petsforum.com/personal/trevo ... inity.html
Good luck.