All My Fish Are Dying

[chilli-spice]

Ok, i think i need a bit of help and a bit of luck.

So far I have lost 1 guppy and 4 platies.

The platies were added on monday last week.

I don't have my own test kit (but will definitely invest in one at the beginning of next month, i just dont have the money right now)

I got my water checked at my LFS
Ammonia - 0
NitrItes - 0
NitrAtes - 10ppm

Tank:
Juwel Rio 180

Stocking:
3 opaline gouramie
6 guppies + 2 fry (was 7 guppies)
6 platies (was 10)

Symptoms:
Some Platies have white substance on them. Not enough to show up in a picture.
Right before they die they become lethargic and refuse to eat.

No erratic swimming, no darting, no tilting etc.
None of the guppies showing symptoms
None of the gouramie showing symptoms.

Really wish I hadn't shunned the use of test kits now

Tank has 7 live plants and a few fake ones.
There are some "hitchhiker" snails.
Started off with just 2, now there are 5 or 6 (i only include as I know this can be a sign of other problems)

I feed flakes twice a day.
My LFS doesn't have live food, I was instructed to by some, but need to wait until I can get to a store further away that sells it.

Did a 50% change yesterday.
Did a 40% today
I then put in King British Fin Rot and Fungus control - 5 capfuls as my tank is 44 gallons.

I don't have another tank to move fish to, so I have had to treat them all.
(Again, I see the errors of my ways. I will invest in a small Q tank / hospital tank when I have money next month)

Is there anything else I can do?
Or have I done anything wrong?

The KB can't be used with aquarium salts.
I was originally gonna buy aquarium salts as an "in the meantime" type thing. But the store didn't have any, so I got the fin rot and fungus control solution.

Probably have screwed it all up, but if anyone can advise me so I don't lose my whole tank, I'd really appreciate it.

 

[the biffster]

how long as the tank been
up and running

 

[chilli-spice]

about 2 months.
i change 30% water every 2/3 days
(discussed in another thread, didnt know about fishless cycle til it was too late)

 

[the biffster]

there's nothing i can say
really until you get yourself
a test kit and we find out what
your stats are i never trust lfs
doing test they always say every
thing is fine to get you to spend more
money in there shop just keep doing
the regular water changes till you
get your test kit

 

[N0body Of The Goat]

How much do you trust your favourite LFS?

Perhaps it might be worth carefully netting all your fish using two nets and taking them to the store for an inspection?

 

[chilli-spice]

I may be using the term LFS loosely.
It's a local pet shop who happen to sell fish.
I trust them, because I went to school with the guy who runs it, but doubt that they would be able to tell me what was wrong. the fish are always healthy and all animals are always well taken care of.

The store I bought the platies from (and who would have the knowledge to help) is about 45 minutes away. So it isn't really worth the stress it would cause to take them all that way if that makes sense?
(its 45 minutes total including a bus journey)