Lost my first fish...

[JustinSmi86]

It's a long shot by any means but is there any chance it's just a moult? Maybe? Trying to find the least alarming possibilities, because the alternative *if* the two deaths are related (they might not be, and it's just bad timing) is chemical contaminants in the tank. I'm unaware of any diseases that kill both fish and shrimp.

Another option if these deaths are happening overnight, is oxygen depletion. What filtration and surface water movement do you have? I can just make out what looks like a HOB filter in your pics, is that all that's breaking the surface in a 75gal tank? It may be insufficient. Keep in mind that, a few week or two after transplanting rock and/or sand from another system, some existing bacteria will have died off and is now repopulating. Bacteria also consume oxygen.

If you have an LFS nearby I would get over there and pick up some polyfilter chemical filtration pads. They'll remove a lot of contaminants from the water and change colour to indicate certain contaminants.

Have some carbon on hand in a reactor ready to go also. If the aeration is insufficient, a bigger filter, a hang on skimmer or an air pump and airstone.

I’ve got two 565 gph powerheads as well. I added carbon to the filter yesterday (just in case). I’ll pick up some of the poly filters as I was headed to fish store today anyways to pick up a 20gallon in an attempt a diy sump.

 

[W1ngz]

I’ve got two 565 gph powerheads as well.

Do they break the surface of the water? A powerhead moving water in the middle or bottom of the tank won't do much for gas exchange at the surface.

 

[JustinSmi86]

Do they break the surface of the water? A powerhead moving water in the middle or bottom of the tank won't do much for gas exchange at the surface.

I have one pointed at surface. Have 1060gph coming in tomorrow so will pick up a cheap pump and air stone today as well.

 

[JustinSmi86]

Added the air stone. Hopefully no more die off before my bigger power heads come in...

 

[JustinSmi86]

Thanks for the troubleshooting and advice! After my temporary fix with the air stones I have not seen my tank so active outside of feeding! I definitely think it was o2 depletion.

 

[W1ngz]

Sounds like good news, but they may just be agitated due to the bubbles. Nothing good happens that fast.

I wouldn't make any decisions for at least a week.

 

[JustinSmi86]

Sounds like good news, but they may just be agitated due to the bubbles. Nothing good happens that fast.

I wouldn't make any decisions for at least a week.

Nothing seems to avoiding the corner of the tank where it is at. I’m guessing that’s a good sign?

 

[JustinSmi86]

Update. No more losses after adding bubbler. I did add protein skimmer, 1050 gph powerh head and a 1200 gph powerhead. No new losses and successful in adding my new live stock out of quarantine. I realize I had no where near the flow I needed. Just glad we caught it before losses were more devestating. Thanks all!