Recently, I downloaded a texture pack and used it in 1.8.9. Everything was fine but the enchantment glint on the splash potions and the drinkable potions (only). The enchantment glint was so messed up it made me drop 700 fps. I tried using the pack on 1.7 and everything was fine on it. The enchantment glint wasn’t messed up. I wanted to use the pack on 1.8.9 but I couldn’t handle the lag on the potions. So, I tried taking files from 1.7.10 that make up the enchantment glint and put it in 1.8.9. But nothing would work. There are no mods or packs that are for my needs. (I need the enchantment glint to change appearance in the hotbar and while being held.) Also, if you download the pack and use it in 1.8.9 then look at the potion enchantment glint in game, you will see what I mean. It gives a massive fps drop.
The attachments below show the difference in fps when I have the potion shown on my screen and different items.