Thanks 
I removed all the substrate at once (black sand) and added a brownish colored sand- 20% water change after I added it
I haven't used any meds in that tank at all except water dechlorinator with every weekly water change
I just checked the stats-.30ppm ammonia- huge improvement compared to last week. Also, no nitrate or nitrite
I brought the other cory back so now there are only 5 neons in the tank
I removed all the substrate at once (black sand) and added a brownish colored sand- 20% water change after I added it
I haven't used any meds in that tank at all except water dechlorinator with every weekly water change
I just checked the stats-.30ppm ammonia- huge improvement compared to last week. Also, no nitrate or nitrite
I brought the other cory back so now there are only 5 neons in the tank
