Why could my urchin be losing spines

[wasabi bean]

So i have had this urchin for two weeks now, i acclimated it over 2 hours whilst floating in the tabk to maintain temp, i previously had another blue tux urchin for years with no issues until i tried a supposedly reef safe treatment to help with ich while setting up qt. It has been about 5 months since that so i bought a new one and it seems to be struggling and has lost a few rows of spines. Here are my parameters:
Ca - 445

Po4 - 0.1

Kh - 9.3

Mg - 1320

No3 - 12
I am not worried about food either as my tank grows lots of algea especially bubble algae which I thought it might help with a bit. Btw the floating stuff is a sheet of nori that went through the powerhead and i checked but all the fish dont bother it

 

[exnisstech]

Do you know if it's wild caught or captive bred? I see both for sale around here. The captive bred are more expensive but have been hardier IME tho I have better luck keeping pin cushion urchins long term vs tuxedos.

 

[JoJosReef]

What was the ich treatment you used? Presume you used it in-tank with your live rock and sand. Did it have copper? It's possible the rocks will continue to release whatever was in the treatment that it bound up while using it. Tux urchins are quite sensitive to parameter swings, including salinity. Is your salinity very stable?

 

[wasabi bean]

It was oodinex which i believe is copper free and for the month after i ran lots of carbon but i haven’t changed it in while so i guess it could be some sort of toxin?

 

[wasabi bean]

Do you know if it's wild caught or captive bred? I see both for sale around here. The captive bred are more expensive but have been hardier IME tho I have better luck keeping pin cushion urchins long term vs tuxedos.

I have no clue but because i am in the uk im guessing they are all captive bred and got the exact same type from my local store, he did take it out of water when i bought it so maybe that caused a problem?

 

[wasabi bean]

What was the ich treatment you used? Presume you used it in-tank with your live rock and sand. Did it have copper? It's possible the rocks will continue to release whatever was in the treatment that it bound up while using it. Tux urchins are quite sensitive to parameter swings, including salinity. Is your salinity very stable?

Yeah i have a good ATO and i do routinely check it with my other parameters and it is always 1.026

 

[JoJosReef]

Yeah i have a good ATO and i do routinely check it with my other parameters and it is always 1.026

Don't think it was time out of the water. They do OK with transfers, and, whilst I don't see tux urchins, seeing other urchins in tide pools out of water frequently, I don't think it's too much of a problem.

My best guess is still something leaching from the rocks/sand or possibly just a specimen that wasn't in great shape and was on its way out.

 

[wasabi bean]

Don't think it was time out of the water. They do OK with transfers, and, whilst I don't see tux urchins, seeing other urchins in tide pools out of water frequently, I don't think it's too much of a problem.

My best guess is still something leaching from the rocks/sand or possibly just a specimen that wasn't in great shape and was on its way out.

Ok i will put in a lot more carbon, but it gives me a little piece of mind that i haven’t done something completely wrong