Does anyone know what disease this is?

[Sunny Doan]

I've been getting this sickness for two of my male nanochromis. And several other apistos. All which have passed now. However, it is only apistos and my nanochromis, my rams seem to be doing fine in the tank. The only difference between that tank and others is it is dirted and is capped with sand. Any issues with this sand causing diseases? https://www.homedepot.com/p/Cemex-50-lb-30-Mesh-Sand-200000278/100321932 Its weird since these fish can go fine for months and then out of the blue contract a disease and die off. This time the nanochromis seems to have a large bump on its head, I have moved him from the sand in case that was the causing factor. 

[Colu]

What are your water parameters and what meds have you treated with

Edited June 23, 2021 by Colu

[Sunny Doan]

On 6/23/2021 at 8:21 AM, Colu said:

What are your water parameters and what meds have you treated with

20-30 nitrate, 0 nitrite, 0 ammonia. Ive only treated with salt, I havent used any other type of med since I didnt know whether it was bacterial or parasitical. 

[Colu]

What I would do is treat with seachems metroplex as it treat bacterial and parasitic infection to cover all bases  

[BIG GREEN]

looks like hole in the head, not sure thhough but what @Colu has suggested to use would treat that also.

If your fish is still eating get some seachem focus also, mix the focus and metroplex together with food and feed.

If your not sure just follow the directions on the bottles...