Planted tank - I think internal parasites?

[anniecox]

I have a 45g. planted tank. I lost a male Neon Dwarf Rainbow a few weeks ago to the same problems a female just developed probably 3 days ago. Enlarged belly, heavy breathing, lethargic. I noticed the swollen belly at least a week or more ago. Was hoping it wasn't the same problem. I am thinking it is internal parasites. Any suggestions of medication that won't hurt my plants? I just finished loosing most of my tank to ich a couple of months ago. This is getting discouraging!

Water quality is good. I do weekly or bi-monthly water changes. Thanks.