Brackish bioactive system. Plant/animal suggestions needed

[sagedrake690]

Hey guys! Im upgrading my saltwater estuary tank. Its a brackish water tank at .17 gravity. It can get up to 20 with evaporation over a few days. I top it off with fresh water. The focus of the tank is my horseshoe crabs. I have 4 and have begun acclimating dwarf hairgrass and another grass to the brackish environment as well as some cherry shrimps and common pond snails. Its been a week since I started and the shrimps are at 10. So far Everything is going well. The grasses are still alive and so are the shrimps and snails. The snails are actually wild cought from here in oklahoma but their species varies in its range and they can be also found where fresh water mixes with salt water. Im open to suggestions for stabilizing a bioactive ecosystem. Im gonna get a mangrove in there as the final touch!

 

[sagedrake690]

Acclimating critters

 

[sagedrake690]

Well here are the results. Slowly over a week or so I have acclimated some cherry shrimps and some grasses to tolerate .017-.020 gravity. A brackish system that mimics an estuary habitat. Heres the 2 shrimps. One on a rock and 1 in the grass. A better view of 3 of the 4 horseshoe crabs I have and 1 full view of the entire system. I have yet to add the mangrove pods. Im waiting for them to come in the mail.

The end results will be like this tank. No ferts, filters or co2. Just topping it off with rodi water. I dont even feed them. I dont need to. There are freshwater plankton, microfauna, I occasionally pull out some of that hair algae. Thats it.

 

[MaxTremors]

You’re going to need a much, much larger tank if you want to keep those horsehoe crabs long term. They can live for decades and can get massive. I would also recommend making the sand a little deeper since they like to bury themselves and since they like to eat all of the worms and microfauna that live in the sand. I would recommend getting some live rock or even some mud that’s full of microfauna (garf and I think algae barn sell it) to seed the sand bed with all of the critters that horseshoe crabs like to eat (I know you can feed them prepared foods, but they’ll still benefit from hunting/foraging for food on their own). They are really cool animals and are a lot of fun to keep, but they really need a species only tank (which it sounds like you’re doing).

 

[sagedrake690]

Oh I know that. They get huge. My gf was like what the heck. Lol im gonna make a frag tank coffee table for them. It will be 4x4 ft and have draws underneath etc. 1/4 will be exposed beach sand. At some point if I cant get a big enough area made I will donate them to an aquarium. My goal is my own house built entirely by my own hands. I will be designing an area built into the house to house the mangrove full size and have saltwater area.

 

[MaxTremors]

Oh I know that. They get huge. My gf was like what the heck. Lol im gonna make a frag tank coffee table for them. It will be 4x4 ft and have draws underneath etc. 1/4 will be exposed beach sand. At some point if I cant get a big enough area made I will donate them to an aquarium. My goal is my own house built entirely by my own hands. I will be designing an area built into the house to house the mangrove full size and have saltwater area.

That’s awesome!

 

[sagedrake690]

Bump!!! Im back at square one guys! Over the course of these few months my horseshoe crabs have eaten everything....the porcelain crab and my snail. I still have that big one. The plants are gone too. I only have this mangrove now and it seems to be doing a good job. I broke down and found this nifty filter at the store. Its great for flow, its strong and can be angled to suit your needs!

It has a small foam filter and some carbon inside a plastic cage and with some finagling you can take off a few of the plastic bars and pop it out and clean it all and replace the carbon with new loose carbon.

It works well cause it wont suck up sand. This doesn't mean it can go inside sand!!! Dont bury it in sand, it needs better flow. but as you see this combo of gravel covering the intake helps so food rots down first and then gets trapped in the filter. Its bee 1 month since I got that filter and it keeps the water moving really well and I haven't needed to do a water change. The mangrove seems to be taking out most of the nutrients as no algae is growing...I would still like to get plants in there though. I wanna take the solid gunk and turn it into plants that make O2 and filter more gunk!!!