Curled and veined gills

I'm new to the axolotl world, recently acquired a 2 year old leucistic axolotl. He came in a 10 gallon with a canister filter and bubbler running. I have moved him to a 20 gal tall (am hoping to move him to a 20 long or bigger soon) and have a canister filter running. He's eating sinking shrimp pellets and bloodworms.
His gills seem to be very curled to me which my understanding is indicates too much water flow. The filter is submerged and I have some plants so I don't feel like this could be the issue. I have also tried turning off the filter and cleaning the tank daily to see if that changed anything, which it didn't.
His gills also have dark colored veins running through them. I have seen pictures of axolotls that look like this so could it be his normal look? He wasn't vein-y like that when I first got him, but his gills were curled.
Any advice?
Thank you!

Are they curled back or curled forward? Stress can make a axolotl curl it's gills back or it could just be the axolotls preference to keep them near the body. Visible veins appearing and them disappearing is normal. Depends how active the axolotl is. When there is more blood flow the veins are more visible.

A light current is great for an axolotl. Stronger currents may bother it.

You have any pics?

Here are some pictures (assuming I figured out how to upload them appropriately). He eats great and is fairly active. The veins seem to be present all the time, not just when he's active.

upload pics round 2

He looks fine.

Gills aren't curled, and veins are how blood travels into/out of the gills. They should be visible in light colored axies.

If your filter is causing too much current, you should replace or refurbish it in such a way to prevent as much current as possible. It's not a good idea to turn your filter off for any period of time.