New Betta behaviour

Hi all, long time since last post as all has been well!

So, I recently lost a Betta I’ve had for over 2 years due to age as no illness apparent, and he’s been replaced (Sunday)

The new guy was acclimated (floated for 20mins then slowly exchanged water in bag with tank water over 1 hour) Sunday into the same tank, which has been up and running for the 2 years. On Sunday he was fine and was swimmimg around up and down the tank, in a Betta log and flaring at me a bit

since Sunday, all he’s been doing is hiding behind the (artificial but silk) plants and tree decor, he is eating ok but it’s a chore to get him to come up for food. He also seems to have clamped tail fins.

when he does come out he’s whizzing about up and down the glass pretty quickly then disappears again for hours on end and brushing the plant decor. Never see him swimming about. Same behaviour now for 4 days

parameters wise : Amm 0 Nitri 0 Nitra 20/30
Heated to 27.7 degrees C
I’ve done 1 30% change since Sunday and usually do 2 per week
Tank is a 30 litre with Oase filter
There’s 2 JBL nano catappa leaves in there with some Silvinia minima floaters

Can’t see any spots, I’ve shone a light on him when he rests on the catappa leaves and can’t see any gold spots or any symptoms of disease other then the clamped fins

I’ve left the light off for 2/3 days this week but hasn’t helped

He gets fed Fluval bug bites or soaked pre feeding in either garlic guard or vita chem and I’ve given him 1 feeding this week of frozen bloodworms/daphnia

It’s just his behaviour, hiding and whizzing about when he does come out which isn’t often!
Couple of tank photos attached for reference

Any other insights? I use prime for dechlorinator and have used stress guard before.

Thanks in advance

 

I would get the nitrates down below 20-30 just to be safe. Are you sure it's not the filter being too strong for him?

 

Thanks - filter is set to lowest setting, it skims the top surface of the water and is set to low. Also the flow is broken up by floating salvinia.

it doesn’t push him around

Cheers

 

Same story today - he isn’t coming out, right at the back end of the tank out of sight behind the plants and tree decoration.

Doesn’t even respond if I either gently tap the lid or break the water with a gentle splash..

This is the 5th day of this now

Struggling with this one

 

Can you get a picture of him?

 

A while ago my nitrates spiked to 20 ppm due to rotting plant matter and I noticed my betta hiding a lot more/being quite skittish. He had no desire to interact with me during that time. After getting them back to his usual range of 5-10ppm he's back to exploring and acting like himself. Just my experience, try lowering your nitrates.

edit: it could also just be his personality, and the fact he's acclimating to a new environment. My betta's personality is on the timid side so I try not to agitate the water or tap the glass because it spooks him.