my discus losing a parasite battle

Hi everyone, was just wondering if anyone could help me with a battling issue I’ve had with my discus that has been ongoing from the day I purchased them. Two of my discus have severely had symptoms of this parasite (I think) unfortunately the smallest one passed away a few weeks ago, but the other one still has it and he is starting to look as bad as the one that passed away, one of my other medium sized discus also has it but is no where near as bad as the other one. I bought all the discus from the same place, at the same time, they are all the same age, the healthy one’s are Nearly 4 times as big as the discus with the parasite, in the picture above! It is eating fine, but loosing a lot of weight, hardly any colour, it is very pale, the ill discus is getting a pin head, it did have fin rot but this has been treated(not sure if it’s related to this issue) it’s starting to get on my nerves now as I’ve spent a lot of money, it’s a fighting battle that I’m loosing. I used to have a ph monitor but it broke, I am using the ph strips to read the ph, this is 6.8, my nitrites and nitrates are fine according to the strip test, the gh is fine according to test, and apparently my kh is high according to the strip test and gh/kh liquid test is also also saying the same. And also Ammonia is fine according to the test as well. I do water changes either everyday or every other day(25% WC, it’s a 300litre tank btw) medications that I have used are:
-discus wormer pre mix
-esha hexameter
-copper (low and high dose)
Due to me living in the uk I can’t get the main active ingredients like metro and Prazi pro and general cure and all the other medicines that I have been told to use on the web.
At the moment I have started anti crustacean parasite by interpet and I have just made up some med food which had quarter teaspoon epsom salt, with 2 crushed gloves of garlic mixed in the the food and also a dash of flubendazole, the food that I have mixed it with is new life spectrum discus formula. I was feeding them beef heart that I bought but I’m not sure if it has blood worms in it as I don’t have the original packet anymore. I’ve stopped feeding them as I have read that blood worms can cause parasite’s apparently. I hope some friendly hobbyists will be able to help me out because I don’t want this to stop me from carrying on my hobby.

What parasite are you treating for and why do you think it's in your system? You did a good job at providing some basic information, but we'd like to see some more specifics. Can you copy/paste the questionnaire found on this link?

http://forum.simplydiscus.com/showth...lease-complete

Problem

1. Please explain the problems with your fish. When did you notice the problems and did anything unusual happen that you think started them? I noticed this fish losing weight as soon as the other one died and and just a couple month after I bought them so about 6/7months ago


2. Symptoms (i.e. turning dark, excess slime, not eating, clamped fins, flashing, darting, clamped gills, white/yellow/green poop, hiding, headstanding or tailstanding, white on tips of fins, rotting or fungus, blisters/white zits on fish, bloated, cloudy eyes, wounds).
Not interacting, going off food loosing a lot of weight

3. What medications/ treatments have you already tried and what were the results. Include dosage and duration of treatment.
anti parasite/dewormer, Esha dewormer, copper and no succes


Tank/Water

4. Tank size and ages, numbers and sizes of fish.
8month old, 300l & 5 discus

5. Water change regime (What percentage and how often).
25% daily or every other day, to mix with tap, 20% tap, 80%ro

6. How long has tank been running? Is it bare bottom? If you have substrate, what type and how deep is it? Running for 27months and and yes bare bottom


7. Do you age your water? If you do for how long and what is the ph swing. Nope


8. What type/brand water conditioner do you use? Do you add it to the tank or aging barrel? How much do you use? Into the barrel and I use 2.5ml in a bin size container and the brand is easy life aqua maker


9. Parameters and water source;

Note: Water Parameters are important in diagnosing problems within a tank. If you don't own test kits for the following information, you can purchase them, test your parameters and post this info as soon as possible.


- temp _____31

- ph _____ 6.8

- ammonia reading ____test kit says it’s in the normal field

- nitrite reading ____ _test kit says it’s in the normal field

- nitrate reading ____ _test kit says it’s in the normal field

What type of water or combinations of water sources do you use? If it is an RO/tap/well water mix, please list percentages in the mix.

- well water ____

- municipal water ____

- RO water ____%80 and 20%tap


10. Any new fish, plants or inverts added recently. nope


11. Please tell us what you feed your fish and how often. This can be critical information for solving the problem so be as specific as you can. New life spectrum and beef heart but I stopped feeding them beef heart as I don’t no if it has bloodworm in it as I have been told it can cause parasites apparently



12. Include any pictures or videos you have which shows the symptoms. If you can't add them to this post, please provide a link to them.

I've never heard of easy life aqua maker but I looked at the product page and I don't see any real issue with this.

I'd like to see specific values of nitrates and nitrites but it seems your test kit is not exact.

Have you ever noticed any white stringy feces?

Do you know what the main ingredient in the discus wormer pre mix is?

Is the seller an importer or local breeder? If importer, do you know the source?