Rummynose Tetra

Hello all, newbie here. Got a Fluval 90l tank, well planted. Done a fishless cycle and have had fish in for about 6 weeks. Before yesterday had lost 1 Rummy and 1 Cardinal tetra, both of these were lost introducing them too the tank and I just put it down to the stress of the move.

Whilst the school of Rummy was down to 5 I wasn't too bothered as one of the White Fin BentosI tetra schooled with it a lot.

However issues have ramped up this week since we introduced 3 JulI Corys. They were introduced on Wednesday and are loving life to be honest. However a Dwarf Gourami passed yesterday, we purchased two as feature fish and the red one which passed never seemed to settle if truth be told.

Now today a Rummy has passed, it looked very ill this morning and was gone by midday. I done a 20l water change as a result. PH is a steady 6.8, water is hard and water quality has been monitored well and very good. No ammonia, no nitrite.

Another Rummy is already looking like he's not likely to make the end of the day. There's nothing visibly wrong with any of the other two, and this morning 3 of the 4 were looking healthy. I'm putting it down to the stress of a diminishing school? And that the Gourami was simply an unhappy fish!

 

How much are you nitrates. What about temperature? Do you use any chemicals?

Definitely sounds like there is a water problem.

 

Temp is 27.
Nitrates 24ppm.

Only use API Stresscoat with water changes.

The remaining Rummynose are all still there. The biggest one is the brightest in terms of redness. One still looks ill as far as I'm concerned. Might just be paranoia on my part. Really confused too, as I was initially concerned with quality and tested immediately, doing a water change irrespective.

Cardinal Tetra all healthy and fully functional. Same too with the White Fin BentosI Tetra (although paranoia again led to me wondering if they were that red in the face before). Sole Dwarf Gourami is acting normal and the JulI Corys are loving life in the air stone bubbles.

Would have thought that a water problem would have been evident across the board in terms of fish health?

Nitrates spiked before which I believe was over feeding.

I'm going to take a water sample too a LFS tomorrow to test it. Could be my API kit is knackered, had it second hand.

 

Definitely the water. Something has happened. A cardinal was floating on top this morning and a white fin bentosI is swimming diagonally if that makes sense. Going to get a new master kit. Done a 70% water change this morning.

Gutted isn't the word.

 

So. Turns out that my heater was out of the socket. Whilst I've been checking the temp during the day, the heat no doubt has helped keep it at a good temperature. Consistent at 25. In the night however, I'm assuming the temp had been dipping and perhaps this could explain the losses? No losses since it's been plugged back in.