Rasboras dying

My harlequin rasboras are dying. We do weekly water changes and testing and all levels are fine. We did just add in an assassin snail. Pics of one of the dead ones below and i currently have one in the tank that seems pale. Whats also really weird is mid week my dawf gourami was on the ground and seemed like he was gonna die then up the next morning like nothing happened, been 6 days with him acting fine. Any suggestions on what i should do? I have had the harlequins for about 3 months.

Stock is 2 dawf gourmies, bristlenose pleco, 8 tetras, 8 corys and now 6 rasbora in a 39 gallon tank.

 

My harlequin rasboras are dying. We do weekly water changes and testing and all levels are fine. We did just add in an assassin snail. Pics of one of the dead ones below and i currently have one in the tank that seems pale. Whats also really weird is mid week my dawf gourami was on the ground and seemed like he was gonna die then up the next morning like nothing happened, been 6 days with him acting fine. Any suggestions on what i should do? I have had the harlequins for about 3 months.

Stock is 2 dawf gourmies, bristlenose pleco, 8 tetras, 8 corys and now 6 rasbora in a 39 gallon tank.

What exactly are your water parameters? Ammonia, nitrite and nitrate.

About your Dwarf Gourami. . . Are you seeing any aggression between them?

 

Ammonia 0
nitrate 0
Ph is between 6.8 and 7
Water has always been a bit hard
Moderate alkaline
No we havent seen aggression had them for 7 months.

 

No nitrite test? When fish are acting off or dying, I always ask about water quality. In your case, I also asked because your profile says you’re not familiar with the nitrogen cycle?

When did you last test? Before or after a water change? What are you using to test and how long has the tank been running?

Assuming you have 2 male Dwarf Gourami, keep a close eye on them. Aggression could (will?) become a problem.

 

Sorry, I have read about it, just haven't changed my profile since i signed up, nitrate and nitrite are zero. For ammonia i use the api kit. For the rest we use the easy strips. We did a water change thursday and just tested the water right before I posted this. Tank has been up since march.

 

My harlequin rasboras are dying. We do weekly water changes and testing and all levels are fine. We did just add in an assassin snail. Pics of one of the dead ones below and i currently have one in the tank that seems pale. Whats also really weird is mid week my dawf gourami was on the ground and seemed like he was gonna die then up the next morning like nothing happened, been 6 days with him acting fine. Any suggestions on what i should do? I have had the harlequins for about 3 months.

Stock is 2 dawf gourmies, bristlenose pleco, 8 tetras, 8 corys and now 6 rasbora in a 39 gallon tank.

Have you quarantined fish as you added them to your tank or anything? They don’t look skinny but it’s possible it could be internal parasites or another disease if they weren’t quarantined.

 

It’s possible you got a weak batch of Rasboras.

What’s your water temperature? And are you adding chemicals of any sort to the tank?

It’s unusual to not have any nitrates in a fully cycled tank. I’d suggest you get the full API Master Test kit.

 

72 temp and adding tetra aquasafe plus conditioner weekly.

I didnt quarantine, i understand in the future to do so but I didn't here. They have all been in the tank for almost 2 months though just the new assassin snail. Anything I can do or just watch them die off...

 

72 temp and adding tetra aquasafe plus conditioner weekly.

I didnt quarantine, i understand in the future to do so but I didn't here. They have all been in the tank for almost 2 months though just the new assassin snail. Anything I can do or just watch them die off...

I’m curious about your water temperature. . . .

While you might be on the very low end of the range for Harlequins, is there a reason you’re keeping the tank at 72?

Have you researched the temperature requirements for your stock?

 

How long after a water change are they dying? Any symptoms before they die?
And what are your source water parameters and do you temperature match to the tank the water you are adding?
Public water or well water?
And I agree that it is strange to not have nitrates. Is the tank heavily planted?

 

Tank is heavily planted. I dont have a heater that I can specifically set to a degree. I have public water. The symptoms started showing probably 3 days after water change. The rasboras are pale and another one died today. I am worried about the tank and all my other fish but I dont know what else to do. I ordered the full api test kit as the store doesn't have one.