Is The Nightmare About Over?

So I posted last week about overstocking my 10 gal here: Help - Did I Overstock My Tank? Two Fish Died.

I have since lost several fish because of my mistake. I know now about overcrowding as well as the importance of larger schools. I unfortunately took the advice from a fella at my LFS.

Here is what remains.

• 2 Pearl Danio (not CPD)
• 1 Longtail Zebra Danio
• 1 Harleqin Rasbora
• 1 Male Guppy
• 1 Male Swordtail
• 2 Splittail Rainbow Furcata (1 male 1 female)
• 2 Pygmy Cory
• 2 Horned Nerite Snails
• 1 Crypt Plant
• 1 Java Moss
• 1 Marimo Ball

Again, it's a 10 gal with Tetra PF10 filter, heater, sponge filter, and a bubbler stone.

• Temp 77f
• Ammonia 0 ppm
• Nitrite 0 ppm
• Nitrate <30 ppm
• pH 7.8
• Tank was started in November.
• Naturally cycled.
• Plants introduced in December near end of cycle
• Fish introduced late December/early January

Now on to my question. Given this info, do you all think the worst is over or will they keep dying because they are not in schools to make them comfortable? They are all small fish so I can't imagine that they are crowded but I could be wrong.

 

They may be small now but some will definitely out grow your tank. As they grow their bio load will increase as well

 

I think the main problem is definitely the schooling-- Rasbora need 5-6 minimum as they are social fish c: And the same goes for Corys-- 3 minimum, but 5-6 is ideal for a healthy social environment. Danios also need schools. Maybe get rid of the larger fish {Guppy and Swordtail} And up the schooling fish, or do it the other way around? All of your fish are social and enjoy their own species company. Or have a school of your choice. But the problem is with Corys for an ideal school you'd perhaps need a bigger tank.
Ideally you would sadly have to remove more of your fish :c It's not about ammonia and such, more quality of life-- they need space and others of their kind. I would perhaps in a 10G have 3-5 Swordtails or Guppys, with the snails and plants. I think keeping anything else in the tank with them would be pushing it a tad. I'm sorry you had to find out this way! I did the same thing, had a 10G and overstocked. I upgraded to a 25G and I love having the space-- my Corys dart all over the tank in their school, it's really pretty! I hoped this helped <3

 

Sorry you got such terrible and misguided information.
If it were me, and this is easier said than done, but I would rehome or take all the fish back and start over. About the only fish you could keep to start a school is the rasbora or maybe a specie only tank with the furcata but they really should be in a 20 gal+.

 

This is hard but we see it a lot. Once someone has problems they start searching the web for answers. That is usually when they end up here. Before that, they trust their lfs to guide them in the right direction. The pygmy cories, guppy and nerite snails are okay for the 10 gallon but the rest of the fish are not. The rasbora is close but since they are schooling, it's not a good idea.

 

At the moment you are probably ok but long term you wil either have to get rid of most of your fish or if space allows and a much happier out come would be to upgrade into something 29+ gallons.