Help!! Sea urchin dying?!

[Ladyregena]

I have a 29 gallon salt water tank with live rock, sand, hawk fish, puffer and 2 small iridescent fish (I forgot what they were). Nitrites are zero and nitrates are very low. I have had the sea urchin say 2.5 months. He was very active at first... About two weeks ago, he began losing a lot of spines... Nitrates were higher and I did a couple big water changes and began feeding him by hand pieces of dried seaweed and clam... He picked up momentum again for a few days but now is back to low energy... What am I missing? I haven't been able to find much info on the little guys... If he is starving, what can I provide for him? I've read they can make a come back but I don't know what to do at this point besides continuing to hand feed maybe?! Thanks ahead!

[Sniperhank]

The issue at hand is nutrients in the water column. Having detectable nitrites is poisonous. This isn't just for inverts like your urchin, but all livestock in the system.
Urchins will loose spines when they are not healthy and stressed. Inverts in general are very sensitive to the parameters in the water column. This is to include high nitrates.
So the first thing that needs to happen is to simply stop everything. Adding more food into the system is going to make matters worse. Large water changes need to be done to get the parameters in the system in check.
With that said, can you tell us more about the system? How long as it been running, how much rock and sand is in the system, so on?

[Ladyregena]

Maybe I described my situation incorrectly but I don't have a nitrite problem, they are at zero. My nitrates were low but they did exist, I think 5-10 ppm off the top of my head since I'm not home to check my notes. Anyways, my water has been correct for about 2 weeks now and after a brief period of being back to super activity, he is not doing well. So what I am trying to ask is what else could be wrong and how can I help? I read it was most likely water quality or starvation so I've been researching the starvation option since my water quality is good! I have had this tank for about two years. It has a sand and coral substrate mix with one live rock and several regular rocks.

[Sniperhank]

Well, if your tank is cycled then all of your rocks are live. Live really points towards the beneficial bacteria base that builds up through the cycling process.

What test kits are you using if you don't mine me asking? In a smaller tank, it is hard to see there being a good amount of fish in a system not producing higher nitrate levels. Tie that in with adding food for the urchin, I would expect the reading to be higher.
Is there algae or cyano growth in the system? If so, there could be enough that is consuming nitrate at a rate that the test kit isn't picking up.

[Ladyregena]

I have both dip strips and dropper tests but I also have algae

[Sniperhank]

Well, the strip tests are far from accurate. Who made the liquid tests, API?
I would ensure that you are doing water changes with ro/di water to ensure that nothing is coming into the system through the water changes.
Cut back on feeding as well to ensure you aren't jacking the parameters more than they most likely are.
I have an urchin in my system. It shed all of its spins when first acclimated into the system, even after a long drip acclimation. It cruises around the system, but does stop for long periods of time. Could be anything from eating something there or a nap or something. Activity can vary from day to night as well.

[Ladyregena]

Yes it's api and I use it on water changes. I only use the dip strips randomly. We also have good well water, so I'm not sure what could pass through. So if there's algae, should I assume he's eating or does he only eat certain algaes?

[Sniperhank]

I'm sure it is consuming the algae.

[Ladyregena]

Was your sea urchin still active when he lost his spines? He has now lost all his spines on his entire visible body however around his mouth and bottom he seems full still. I cannot tell if he has little spines coming in or if they are the softer underneath layer.

[Sniperhank]

He didn't loose all his spines.