Help! My Fish Keep Dying :(

Hello all! I've had a 20 gallon freshwater tank setup for about 6 months now. It's been cycled for 5 months and I've had fish in it since then. I used to have 17 fish (various types of tetras), and now I'm down to 7 I bought 4 Rummynose Tetra's from a LFS a few weeks back. They looked completely healthy and I didn't notice anything unusual. I brought them back to my office and put them in the tank (acclimated first of course). Over 24 hours, I lost 6 fish. I noticed little white spots all over the Rummynoses' and three of them died within the first 2 days. Then more and more of my fish have been dying since then. I've been treating the tank with Parasite Remedy from imagitarium for the past 2 weeks but I kept losing more of my fish slowly. I lost my last neon tetra this morning and I'm very upset because I don't know what's going on.

Here are my water parameters:

Nitrite = 0
Ammonia = 0
Nitrate = 10-20ppm
PH = 7.4/7.8
Temperature = 78 degrees

I currently have 4 Albino Pristella's and 3 Silvertip's. Oh and 4 Nerite snails.

The filter is a Marina SlI'm S20. I have the carbon removed right now for the treatments. Otherwise I have two packs of bio-clear and purigen for media. I'm attaching a photo for reference. Any help would be greatly appreciated!!!

 

You could try treating ich with temperature instead of medication. Also test your source water. Ammonia is so high in my tap water it is deadly to fish even with conditioner - I have to cycle it in a bucket first- took me a year to figure this out.

 

Sounds like Ich to me and your tank was likely overstocked.

 

I think ADFs are an over-thunked 'fish'. I've kept them with bettas (male and female). Only once did an ADF attack a betta, but that ADF had just come from BigBoxPet and was suffering from starvation. Other than that one instance, I've never had an issue with ADFs biting any fish. In fact, the girl bettas and ADFs constantly bump into each other on the bottom while searching for food. No biting.

 

I'm sorry your fish are dying, that always is sad.

A few thoughts
1) Your tank is VERY sparse. Was it like this when you added all the fish? Not having any shelter or places to hide will stress fish out, making them more susceptible to illness. I would add a lot more decor, fake or live plants, anything to add more areas for the fish to hide.
2) The white spots on the fish definitely sounds like ich.
3) I don't know much about the imagitarium parasite remedy, but some fish are a lot more sensitive to medications than others. I know some meds also deplete oxygen in the tank somehow, perhaps this is one of them?
4) If you don't have a quarantine procedure, I highly recommend starting one. Had the rummynose been in a QT tank, your display tank wouldn't have had ich, so you wouldn't have had to treat all the fish
5) What is the pH of the store water where you are getting the fish? If the pH is significantly lower, that could also be an issue perhaps
6) If the nitrates are constantly closer to 20ppm, that also could be a problem for them if they are particularly sensitive to it

I think ADFs are an over-thunked 'fish'. I've kept them with bettas (male and female). Only once did an ADF attack a betta, but that ADF had just come from BigBoxPet and was suffering from starvation. Other than that one instance, I've never had an issue with ADFs biting any fish. In fact, the girl bettas and ADFs constantly bump into each other on the bottom while searching for food. No biting.

Wrong thread perhaps?