are my harlequin rasboras ok?

[bossboss]

sorry if this is in the wrong place or if there's no real issue. I'm still kinda new to aquarium keeping and this is my first post. my last fish died bc i didn't take action soon enough so i worry about my little guys

tl;dr at the bottom

so I've got a 10g tank, the water is healthy with no ammonia nitrate or nitrite, and I've done what i can to make a happy environment for them.
I've had them for a couple weeks, and after each group got their chance to acclimate to the water and adjust to the environment they were fine and started schooling but they've started splitting up from each other.
I've got 6 right now (i got 3, let the bacteria adjust to the bioload and then got more bc the first 3 were freaking out over the small school size), but except for when i approach the tank they don't stay together at all. a couple have begun to hang out near (not on our against) the gravel. they still move a little but they mostly stay until i approach. there's one that i just noticed has begun to chase the others a bit. i haven't seen any bite marks though. there is another member of the six i know I'll need to put down soon bc he has no external damage but he glass surfs up and down a corner of the tank constantly. i haven't yet bc he still schools with them when they come together and he still eats. I'm also just afraid to, if im being honest.

tl;dr they are not schooling together unless at the front of the tank, some have started hanging near the bottom

 

[tlindsey]

Welcome aboard

The aquarium should have a positive reading of nitrate if aquarium is cycled. If the fish were bought and just put in the aquarium without the aquarium being fully cycled this will lead to ammonia and nitrite. That will definitely cause fish to eventually show signs of behavior like rapid breathing not eating and death. It can take a aquarium up to 6 weeks to cycle.
Do you have dechlorinator?

 

[bossboss]

that's the thing i didn't drop them in the day or even within the week of setting it up.
i used dechlorinated tap water when i initially set it up about 3 months ago and I've had to do several water changes with ro since, then letting it cycle.
i used a bio ball i think it was called to readd a little of the beneficial bacteria in prep for them too.

 

[tlindsey]

just do partial 25% weekly water changes and feed lightly. Test water parameters weekly until all parameters stabilize and you get a positive nitrate reading.

 

[fearlessfisch]

deleted duplicate

 

[fearlessfisch]

The aquarium is not fully cycled, so you will have to do frequent partial water changes until you consistently get readings of zero ammonia, zero nitrite, and positive nitrates. Then you will know the cycle is complete. Make sure you have a liquid test kit, as they are more accurate than strips. Test daily and change as much water as you need to, to keep ammonia and nitrite levels below 0.25 at all times. Any higher than that, and you are stressing your fish and may see signs of distress like you described. Make sure to match water temperature and use a dechlorinator when changing water.



It may take a while, but you will get there. If you want to speed up the process, get some used, wet filter media from a healthy, established aquarium, and put it in your filter.



Good luck.