Fin Rot Fin Rot?

About a week ago, I removed two Gold Red Endlers from their tank because their fins were torn and I thought they were being attacked by the others. It looked like they had big bite marks out of them. Yesterday one died and today the other did. But now more endlers are looking the same. I removed the three juvies, who were looking fine.

A couple of days ago, my Gold Swordtail guppies stopped swimming around and had their tails clamped. I was really sick that day from food poisoning, so I didn't notice a lot about them. Yesterday, I noticed it looked like their fins were being chewed on, too. Everyone of them, and they started shimmying, but they weren't going forward. I did a partial water change yesterday with the siphon and then added a dose of Melafix, because I started to suspect fin rot. I don't know how they could have got it, though because they hadn't been netted in a week.

I added plants the day before, but they were in a clean tank with no fish for a week. I put more plants from that fishless tank in other tanks and other fish are doing fine. I also suspect the Gold Red Endlers may have it, so I added Melafix to them and added fresh water. I had added nothing new to their tank.

Water conditions of both tanks are perfect and they get regular weekly water changes. Does this sound like fin rot? Do I need to turn up or down the temperature? I use the directed amount of Aquarium Salt, but do I need to add more? I have Trapdoor snails in the Gold Red Endler tank. Do I need to do water changes daily or let the medicine take care of it? Is there anything else it can be?

 

She just had fry, so she's really skinny.

 

Yeah, all the guppies in this tank in this tank have their fins like that. There was 4 Gold Swordtail guppies, and nothing else. One male died last night so now I'm down to a trio. The female in this picture had at least nine fry a week ago while I was out, and one was eaten before my eyes. The remaining eight are safe and healthy in their fry tank. I don't know how old she is. I got them two weeks ago and she had fry one week ago.

I lost one of the juvies this morning that I had removed from the Gold Red Endler tank. All but a trio of the Endlers are missing, and two of them have small fin damage. The other two juvies are okay for now, but their fins are too small I can't tell if they're damaged.

 

1) API Freshwater Master Test Kit. I can't find the date, but I got it a few months ago, and had a slight difference in some of my tanks, so I assumed it was working. I have well water, so I don't need to worry about chlorine, and I try not to add chemicals to my tanks.
Guppies -- pH: 7.4, Ammonia: 0, Nitrite: 0, Nitrate: 0
Endlers -- pH: 7.4, Ammonia: .25, Nitrite: 0, Nitrate: 0

2) It was at 78F on both tanks, but I raised it to 80 when they got sick. I didn't know higher temps shorten lifespan. For the guppies: It was originally a fry tank, converted to the adult guppy tank, so it has a sponge filter.

4) For the guppies: No carbon filter, just the sponge filter with the airstone in it. Today is day three on the Melafix treatment. I can run by the petstore and get Pimafix tomorrow. Should I wait until the seven days are up before starting the Pimafix?
For the Endlers: I removed the carbon before using it, but I still have the waterfall filter going.

5) The guppies were sold as two pairs. One of the males died and now I'm down to a trio. Of the Endlers I had 7 female, 3 males, and 3 juvies. Two females and one male died. I took out the juvies before treating. I can only find a trio, the others are missing. One of the three juvies was dead this morning.

The guppies are by themselves in their tank, the endlers only share their tank with trapdoor snails, and I think they were bothering the snails.

 

I didn't know that, I thought it was one male to two females. Most of my tanks are male only or female only, except for my Flame tail Endler tank which is five females and one male, and my Albion Tangerine Guppies, which is two pairs because that's how they were sold. I really hope the store has Pimafix.

Thank you for your help!

 

I was able to run down and get it. I added PimaFix just a few minutes ago. But now one of my female Gold Reds are missing. Now it's down to a pair in that tank... neither them nor the guppies are swimming around, and as of now, the males aren't bothering the females or showing any interest at all. When they get better, I can try to get more Gold Red Endler females. The guppies had eight fry a week ago. Hopefully six are female and two are male, because I won't be able to get any more of them.

 

My Endlers seem to be doing better. They're swimming around more and the male's tail fin is less clamped. I'm still at a trio and two juvies.
My guppies are apparently not doing better, because I lost the female in that photo last night. I'm down to one male and one female.

 

My Endlers are doing... better I think. One female is missing now, but the remaining male and female seem to be doing good. The male's tail isn't clamped anymore, unless the female comes near. The remaining two juvies are doing well, also.
My guppies are not. The last female died last night and now I only have the male and eight fry. The fry are in a fry tank and are healthy. The male's tail is still clamped, but he's swimming around a little more.

 

The tail fin is clamped tight.