Having some issues with a new tank and hoping you all can help!
A little background:
I have a 55 gallon tank that was cycled for over a month before fish were added. Start Zyme and Start Rite as well as a dechlorinater were added. Filter is a Marineland BioWheel 350. Marineland PowerHead is turned on a few hours a day, fish seem to enjoy the current. No live plants. Submersible heater. Light is 12hrs on, 12 hours off, natural light filtered in during the day.
9 fish were originally purchased from Petsmart 2 weeks ago today and put in the tank. 3 sunburst platies, 2 dalmatian mollies, 2 plecos, 2 dwarf gouramis. Fish are being fed Tropical Fish flakes, algae pellets and bottom feeder pellets from API. Water parameters have been tested every other day since the addition of fish and have consistently remained the same.
Alkalinity- 80 moderate
On day 4, I had one platie and my dalmatian molly die. No signs of illness, both very active. Brought them both in to the store, received an exchange for another platie and another dwarf gourami. Water parameters tested = OK.
Day 2 of new additions and the new dwarf gourami starts acting weird, sitting at bottom of tank. Day 4: Dead. One pleco is discovered underneath tree branch, covered in fuzzy substance. Brought back to Petsmart, refund received, no new fish added.
3 days later, one of my original gouramis starts getting white cottony substance around mouth. Next day, he's staying at top of tank, flittering across top of water sucking up air. He is still alive. Go to Petsmart, bring the fish, they tell me its Velvet and to treat the tank for that. I do my own research amongst forums and figure out its cottonmouth. Went back to Petsmart, they tell me to treat it as a fungus, even though I've gotten contradicting information to treat it is a bacteria. To stay safe, I buy Pimafix and Melafix and begin treating the tank for both. Carbon filter taken out, 25% water change done, and this will be day 6 of treatment.
The dalmatian molly for the past 2 days has been acting a touch weird, swimming as if his tail is paralyzed, it hangs down at a weird angle and isn't as active as he usually is.
Last night I notice my Pleco, dalmatian molly and one platy have small white spots on them . Ich! I've read multiple treatment ideas, I have upped my temperature from an average 77 to 80 degrees, and marine salt had previously been introduced into the tank and I have added more. Water parameters tested, still the same as before, all perfect numbers.
WHAT TO DO?!
Should I stop treating with Pimafix/Melafix since none of my fish are displaying any symptoms (there are technically 2 days left in the recommended treatment). Should I begin medicating for Ich? If this is the case, should I do a water change before I treat and then do daily changes? The pet store has Rid-Ich but are there any other recommended medications/actions to take? I'm down to 6 fish in the tank (3 platies, 1 pleco, 1 dwarf gourami, 1 molly) and would love not to lose any more. Please help!
This is my first go at a tank and I am trying to do this right!
Side note: I am told from a Petsmart employee that the week I purchased my fish, the filtration system in the store went down and they had a bunch of fish die as well. As of 5 days ago, the part was still not fixed. I purchased fish 3 times in that time period before I knew the situation they were having. No new fish have been added.