brackish filtration question

[InAtTheDeepEnd]

Tank Plans

 

Juwel Primo 70 litre (60cm long)

1.005sg 

24*c 

pH 7.8-8.0 ish 

Mangroves& hardier sorts of macro

Substrate a mixture of mud (underneath for nutrients for the mangroves)/sand

 

Planned stocking

6 mollies 

5-6 bumblebee gobies 

OR 1 knight goby

 

Best way to filter this - my options are a 300l/hr sponge, 440l/hr hob, or 600l/hr sponge?

 

Anything else I need to consider? I think 70l is pushing it for housing a knight goby but they're not particularly active fish, neither are the bumblebees but they need to be able to shoal and live in large numbers. 

Also can't decide to go with the light on the tank or go open top and let the mangroves get really tall out the top, but then I would worry about anyone jumping.

 

Basically, critique these tank plans, because we all know things can be overlooked in the excitement of setting another one up....and I have wanted a brackish set up for ages now. I love the small species of gobies, but want maintenance to be easy, though, so it might be easier to just stock with mollies for now and see how the parameters go.

 

[seabass]

Personally, I might choose the HOB filter to help make the display look a little less cluttered.

 

I'm not sure what kinds of macroalgae would be happy in a brackish tank.

https://aquariumbreeder.com/brackish-water-plants/

 

https://fishlab.com/brackish-water-aquarium/

https://en.m.wikipedia.org/wiki/List_of_brackish_aquarium_invertebrate_species

 

[Tired]

The website petshrimp.com sells a species of chaeto that can thrive anywhere from brackish to full saltwater, and also some cute little balls of fluffy algae that look like tiny marimo. It's meant for opae ula (brackish-water Hawaiian shrimp) setups, but should do fine for you as well. 

 

You could always do a low water level to minimize jump risk, especially if you go with gobies. Gobies can't get much air. 

[InAtTheDeepEnd]

24 minutes ago, Tired said:

The website petshrimp.com sells a species of chaeto that can thrive anywhere from brackish to full saltwater, and also some cute little balls of fluffy algae that look like tiny marimo. It's meant for opae ula (brackish-water Hawaiian shrimp) setups, but should do fine for you as well. 

 

You could always do a low water level to minimize jump risk, especially if you go with gobies. Gobies can't get much air. 

Yeah thank you, definitely going to keep the water low ish though TBF mollies *can* jump but don't seem very inclined to and gobies definitely are more sedentary fish 

 

I'd totally forgotten about Marimo so thank you for that!!

 😂

[Tired]

It's best practice to assume that, at some point, one of your fish is going to jump. Even if they aren't very inclined, it's always possible, if they're physically capable of doing so. About the only fish physically incapable of jumping is a seahorse. 

 

I'm not sure if Marimo are actually brackish-tolerant. I know these algae ball things are. 

Edit: this https://www.petshrimp.com/beware-of-so-called-brackish-water-plants/ would seem to suggest that Marimo do not enjoy brackish water. This guy keeps those brackish-water shrimp, and there's a whole discussion forum about brackish aquariums. It's centered around these specific shrimp, but the same principles apply. 

[Ratvan]

Anubias Barteri, Java Fern and Java moss do well in low salinity brackish set ups (1.005-1.012) 

I would go for the largest sponge filter that you have in the tank and place it so that it is hidden but also you can remove it easily, probably have the HOB on as well for the start up