Journal 5.5g Halocaridina rubra Tank

[Johnson18]

This is my new 5.5 gallon brackish water Halocaridina rubra tank. Not a planted aquascape but these are pretty cool little shrimp. Commonly called ‘Ōpae’ula, Hawaiian Red Shrimp, or volcano shrimp. They’re endemic to anchialine pools on five of the Hawaiian Islands and can live up to 20 years.

I’ve had a small colony in a 2.5g since 2018. The population took a big hit in 2020-21 following a back injury. I lost more than half of the shrimp. They’ve slowly been recovering. Last fall I found a ~0.75” round chip on the back glass near one corner. Everything seemed fine but I started to make plans for a replacement. I bought a new 5.5 and about 15lb of black lava rock this spring. In late July I noticed the seal opposite the chip developed some salt creep & decided I should actually start the replacement.

Here are the basics of the new set up.

Tank: 5.5 gallon Aqueon tank
DIY glass lid
Light: 18” BuildMyLED 10,000K planted (12” LED board)
Substrate: Aragonite in mesh bags, black sand
Hardscape: Lava rock
Filtration: Topfin low flow internal filter - only while cycling
The 2.5g was set up with left overs from a reef build. It is white coral (bought as dry rock), with aragonite sand with a white & blue led. Not a great set up for these shrimp. I wanted something more natural looking.

The plan was for black lava rock with black sand. The rock I bought was some larger pieces I planned to break down into a variety of usable sizes. When I did so, I found the outer layers to be black with the majority of the rock a bright red. Oh well, I was worth a shot! It’s made a lovely combo of black and red rock on black substrate. Fortunately, the goal is to cover most of the rock in a layer of algae.

Here is a current FTS.


The 2.5

 

[Johnson18]

The original plan for a 5.5g was to fit the same spot as the 2.5g, which is the bottom shelf of one of two identical stands. Not great for viewing being 6” off the ground & no full view of the tank.


Seeing as these shrimp are going to be in my fishroom a long time I wanted to be able to enjoy them easier. I ended up putting the new tank on the top of the second stand, next to my 60p. If I had planned this better the 60p would be a few inches to the right of its location allowing for a 10g. Instead I spaced it for my 60f to sit with the short side forward. Anyways, it’s sitting at the back of the 24”w stand leaving room to work in front of it. This wasn’t the final location but close enough.


For the actual build I wanted the aragonite sand to provide a buffer for the water but did not want white substrate. I traded a local club member some plants for a gallon bag of the sand. That was washed and placed into filter media bags. I used them as a base for the hardscape across the back of the tank.




The rock selection after breaking them up… I tried to leave myself a good variety of sizes. The largest pieces probably could’ve been a little smaller but my back wasn’t having it. Lol.


The sand is some that was in my 90p when I got it. It had a plant substrate mixed in. I used the same type of media bag to sift it out. The largest size sand grain was removed as well, not on purpose but they were too close in size to the mesh.





Since the other tank has obviously developed a slow leak I’d like to get this tank cycled fairly quickly. I cut some filter sponge from the 60p and squeezed water into this tank. The 2.5 is filterless so there’s not really media to transfer over unless I start moving rock. There are a few small pieces I might be able to add without destroying the tank which is really just a couple larger rocks. The salinity is currently 1.015 sg. Not sure the fw nitrifying bacteria will live in that. I did order Fritz Zyme for saltwater. Not a product I’ve ever used but I figured it couldn’t hurt. Fritz recommends switching from the fresh to salt products at 1.015 but said that since I’m right at that SG both would probably be required. I will be adding ammonia throughout the cycling process and until the tank matures enough to support the shrimp.

I DIY’d a glass lid for this tank. Being a filterless, heaterless set up there was no need to have room in the lid for cords or anything. That’s great news for living in the desert (AZ) as there’s less chance for water to evaporate. For most of the year the rimless 60p next to this tank gets 16-24oz of water topped off daily. I checked out the usual cheap glass lid with the two pieces that fold. They were more $ than the tank & would leave me with a gap in the back from the plastic piece. The local hardware store was able to cut me a piece of glass to size from their scraps for $2.00. I spent about an hour wet sanding the edges with progressively finer sandpaper. Once that was done I siliconed on two small glass marble/beads, like you might use around the base of a potted plant, so I can lift it up. The piece of glass was the only purchase. The silicone surprised the hell out of me. It was a tube I got while working on a sunfish sailboat about 2012. Been in a box of boat parts ever since & the boat is long gone. Once the filter goes away it will sit nice and flat. The glass handles are flat enough they don’t stick way above the rim.

 

[Art]

Hey great write up. Thank you!

So are these shrimp brackish shrimp? Love the iwagumi aquascape with dark substrate. Very nice.

Also love the 60p and the grow out tank underneath growing emersed. What do you have in there?!

 

[Johnson18]

Hey great write up. Thank you!

So are these shrimp brackish shrimp? Love the iwagumi aquascape with dark substrate. Very nice.

Also love the 60p and the grow out tank underneath growing emersed. What do you have in there?!

Thanks, Art. Yes, they are a brackish shrimp. Unfortunately, not salty enough for most macro algae though. They were sold/marketed as “Supershrimp” in sealed “ecospheres” at one point. I originally found them through the members of the AZ killifish club (Arizona Rivulin Keepers), those old guys have all the random small things. There used to be maybe 10-12 people I knew up in the Phoenix area that kept them. Asking around this spring when I started planning this tank I could only find 3 remaining.

The scape seems kind of lacking to me with the rocks being on the smaller size. I have never been much of an aquascaper, not enough practice. The 2.5g has always been this wall of rock with no open space. It was great for the shrimp, lots of hiding & surface area. Difficult for viewing, cleaning & a mess of algae near the surface where the rock was only 0.5in below the waterline. Hopefully, this one will be better for maintenance.

The emersed 40B is mostly Cryptocoryne species with a few other semi-aquatic aroids & terrestrial plants mixed in. At one point I had about 175gal of emersed tanks with many of rarer semi-aquatic aroids in the hobby. Lost most of those during 20-21 following the back injury as well. It’s currently a mix of some of the less common species that survived and the common varieties that I had but hadn’t ever gotten to flower. I’ll get a thread started for it at some point.

Speaking of Crypts… The 60p has a C. affinis ‘metallic red’ that is on its second inflorescence this year. Found it a couple days back, it’s still <2” tall.

 

[Art]

I’ll get a thread started for it at some point.

That would be VERY interesting to read. Thanks.

Speaking of Crypts… The 60p has a C. affinis ‘metallic red’ that is on its second inflorescence this year. Found it a couple days back, it’s still <2” tall.

Any pictures?

 

[Johnson18]

That would be VERY interesting to read. Thanks.


Any pictures?

I cut it prior to breaking the surface and tossed it into the plant press. The AZ humidity(or lack of…) means they dry up as soon they break the surface.

The one before this ended with the shrunken top section that would have been 15-20cm tall but was about 4cm, plus the still living submerged section. Didn’t even try to press it.


Since this is in the brackish tank thread, I’ll throw an update here too. It’s had one shrimp since the 16th of January. It’s all I was able to catch out of the 2.5g before a spinal fusion.

In April I added 10-12 Littoridinops monroensis snails, or the Cockscomb Hydrobe. They are a brackish water NA native of the east coast, MD-FL-AL & the Bahamas, with a max recorded size of 4.5mm. A guy in the Ōpae’ula FB group was offering them (tank bred) for shipping alone. The tank was solid algae(glass included) by then & is now down to less than 1/4 left. I even cranked the photoperiod to help maintain it. There’s about a hundred of them now. I tossed a couple into the 2.5g as well. It’s not covered & so they’re breeding much, much slower. If anyone who keeps these shrimp want to try them drop me line. They were given to me with the hope I would spread them further, which is apparently happening quicker than expected. The guy who gave them to me commented he had never seen them explode like mine had. lol

At last month’s Desert Aquarist Society meeting I picked up a bag of Lomariopsis lineata, susswassertang/subwassertang, which I added to this tank. There’s a guy in Phoenix who has a moss wall across the back of his tank, so I figured id give it a try. There was no slow transition, it was separated & tossed in to sink where ever. That was almost 3 weeks ago. There was a little die back which the snails ate over the first week. Since then it appears to have stabilized.

It’s scattered like this all around, plus some chaeto algae that came with the snails.

I bought a second bag that I left freshwater in a half gallon mason jar from the late 1920s. It’s sitting in a south facing window with all of my house plants. It’ll let me try again if needed.

Here are current before/after trim pics of the 29g for the planted aquarium tax!

Sent from my iPhone using Tapatalk

 

[Art]

Hope you're doing better after the spinal fusion.

I really like the simplicity of the planted tank. Great composition.

As to the brackish tank, I can't make heads or tails of what you have growing on the rocks. Is that algae?