Goldfish with white spots on ends of fins

Question
Hello. I have had a 20 gallon tank with a 4" ryukin goldfish (Susie) and a 2" fantail goldfish for 6 months (Corky). Two months ago added bottom feeding algea eater (small variety). Tank has 40 gallon filter because salesgirl suggested due to tank being vertical. Also has small heater that keeps water at constant 71.((  Old house got too cold over winter when Susie was in 10 gallon & went dormant.)) Anyway...5 days ago found algea eater dead. Had small hole in his side & stunk real bad. Did a 50 percent water change. Used distiller water. Next day treated water with clarifier because water was still very murky & water is never murky. Thought it was from dead fish???? Now.... Lots bad.
Susie has tiny white grainy spots on "the ENDS of her beautiful fins." not thru out, nor on body or gills.
Corky has a splattering of this white on his face...like he swam thru white & some got stuck. Have read 10 websites on ich and just don't know because everything mainly says affects body & gills.
Is this ich or from clarifier? Have used clarifier twice before & this didn't happen.
AND can't correct water since dead fish.
Nitrate 0...ok
Nitrite 0...ok
ph  6.
KH. 0.  !
GH. 60.  !

Please please help and thank you kindly.
Tried to attach photo but upload icon not responding.

Answer
Hi Jacqueline!

I'm terribly sorry for this late reply! I never received the email of your question.
The white spots are called Ick, parasites that live on your fish. I suggest you to use the Tetra IckGuard. It's a treatment that effectively kills and prevents Ick. Before using it, you need to turn off the filters otherwise the filter will take out the medication. You can buy this at Petsmart for about $4-$6.


Hope this helps!
~Sam