Riah's note in a bottle quest

[Ichor_Tears]

So I found the grey bottle in the ocean. I then found the red one in the mines. I looked at a discussion on here that said the blue one was in the mines where the blue mushroom cave is but I only found a bunch of red bottles. I tried fishing at the lake you make for riah (if that is the lake since I am not sure) and I can't find the blue bottle! Someone please help!

[ExplodeySquirrel]

(Spoilers ahead!)
For Riah's quest, you just need to fish on 3 different kinds of water tiles:

1. Pond water → blue letter
   
2. Ocean water → grey letter
   
3. Ice water → red letter

The Abandoned Mine has both pond water (orange cave) and ice water (purple cave), so it's easy to get confused on this quest. However, ice water has no normal fish so you can tell right away that it's the wrong cave if you catch something.

If you still don't have any luck with that, you can also wait until the Winter Festival and get the last bottle from the ice water surrounding the shrine.

[Ichor_Tears]

Thank you so much! I have been stuck on this part for a while now!

[Myakka_23]

Your wonderful, thank you so much.

[-Forgotten Shadows-]

i still cant get it :[

[-Forgotten Shadows-]

that mines one i just can't do, im scared of going in the mines for no good reason and i had no luck on ice waters, my thing is a creative world so i got out ALLLLL the waters, and fished for HOURS with NO luck ;b

[Skyfire]

I never had this problem: I only get grey and blue bottles, no matter where I fish! I already have 9 blue bottles but not a red one. I'm going to try the icewater.

I found it in the hidden place where the mushrooms are:
https://steamcommunity.com/sharedfiles/filedetails/?id=3054858278
This is the first time for the red bottle and a played the game many times.