# Opae Ula help



## swimmy

Among my other aquatic endeavors, I decided to try keeping opae ula (hawaiian shrimp often used for seahorse food). I read about a place in Hawaii that sold 1/2 or 3/4 gallon, fully established tanks without filters, and I thought I could set up one myself, so I ordered 20 through the mail (nowhere to get them around here), and they came three days ago. 

Here's the setup:
1/2 gallon vase with sand (boiled before using, just in case), a little gravel and a fern and water from another cycled tank, plus enough salt to make it brackish. The water tested fine (no3: 0, no2: 0, pH: 7, KH: 60) when I put them in, along with some sponges from the supplier, which I assume were there to host beneficial bacteria.

They were all very red and active. I fed a tiny amount of spiralina (like 1 flake). The next day the water looked a little cloudy and one shrimp had died (which I assumed was a result of the trip through the mail), but they all looked a little paler, so I tested the water. The results: no3: 80, no2: 2. I was shocked, since everything but the sand had come from a cycled tank, and I had only fed them once.

I had set up an identical vase because I intend to divide the shrimp with my mother, so I checked the water in the other vase, just in case I had made a mistake before, but the results were normal. So I changed out 50% of the water with water from the other vase and retested with the expected results (no3: 40, no2: 1). I changed 50% again yesterday and today, so now the nitrates are about 20 and the nitrites are about .5 or so.

My concern is that, while some of the shrimp have gotten back their bright red color, some of them are still pale, and three more have died (one today). I wonder if my water levels are still unsafe for keeping shrimp or if the latest casualty is the result of the previous toxicity. I am also worried about feeding them, since such a small amount of food apparently caused such a huge spike. I haven't fed them again. There is a little bit of algae on the fern, but at some point I am going to have to suppliment it with something. I have read that it is okay to go for over a week without feeding these little guys. 

I'm also baffled by how the water spiked so quickly. Like I said, the other vase is identical, including the gravel and fern from the same tank, so it can't be those things. I also separated the sponges that came with the shrimp, thinking they might have contributed, but after 12 hours the water I had them in tested normally. I have also considered that, in spite of what I've read, 1/2 gallon may not be enough to keep opae ula in.

I guess my questions are:
What are safe nitrate/nitrite levels for keeping shrimp?
Is it practical to keep opae ula in an unfiltered 1/2 gallon environment?
Is there anything else I could be doing wrong based on this information?

I would appreciate any help that anyone with experience could give me. Please let me know if there are any details I've left out. Thanks in advance!


----------



## swimmy

*Conclusions I've reached*

There isn't much information out there about keeping shrimp, particularly these little guys. I actually got some great information from petshrimp.com about why shrimp mysteriously die and about opae ula in particular.
It comes down to this (and I apologize to all of my sources for the oversimplification of the vast amount of their knowledge that I've distilled to this little post):
Shrimp die, and sometimes for no measurable reason. Sometimes deaths can be attributed to fluctuations in Ph or other water changes, and sometimes the factor which caused the casualties in your tank can't be quantified. Sometimes the event which caused the stress (water changes, upgrading a tank, adding a plant, accidental introduction of heavy metals or other substances toxic to shrimp) happens and is remedied before you even know that there is a problem.
In my case, it seems that a nitrate spike caused by a single feeding was enough to continue killing shrimp for several days after the water levels returned to normal. Apparently once shrimp have been stressed and become sick, there really isn't much that you can do, except to correct the problem then wait out the consequenses.
After four days of casualties, the last one being the worst, the water levels are all stable, I haven't lost any more shrimp, and all of the survivors are regaining their healthy red coloring.
Hopefully, the nine little troopers I have left can repopulate their depleted family. I certainly have a new appreciation for how fragile these guys really are.
I hope that this post will help someone else who is having the same experience.
:fish:


----------



## SouthernBelle23

Sorry that no one answered your post! I'm glad you were able to find some info though. I have never heard of these shrimps.

And while I have not heard of them, 1/2 gallon seems like a small amount of water to keep them in, especially 20 of them. I feel like a larger tank/vase would probably help their success rates. Alot of shrimp are pretty sensitive to changes in ph and any change in water quality (ammonia or nitrites in the water) so having a larger volume of water would minimize that...especially with a filter.


----------



## swimmy

Thanks for your reply. Yes, larger tanks are much easier to keep up water quality. Something larger would be ideal. I have also recently read that weekly feedings are sufficient for these guys, so it is very easy to overfeed. 
The best source I found recommended 50 opae ula per gallon, as their adult size is about 1.5 centimeters. They are typically used as seahorse food or for those awful little ecospheres, so I don't think much has been published about actually keeping them as pets. They are really interesting, though, and only found wild in Hawaii, where their numbers have been greatly depleted, which is a shame since they are so lovely and even have a place in local mythology. 
For now, they are living happily, with no new casualties, and they are all very red and active again. Their life span has been estimated at 20 years with proper care, so hopefully they will stay that way for a while.


----------

