How to achieve no algae in a non planted tank.

[John Troy]

Im planning on setting up a brackish water aquarium with a focus on hard-scape, I was wondering on the best methodology to achieve no algae and whether this is even possible given I wont be growing plants.
My first thought was to just have no lighting except when viewing, but apparently fish need lighting as well to regulate their circadian rythm.
Im using reminilarised RO water but this doesn't completely remove macro-nutrients given my tap water has 40ppm nitrates to begin with, so I cant entirely limit this.
Is there any other way for me to achieve an algae free tank?

 

[hypnogogia]

Minimal lighting and lots of algae removal when it appears. As it's fish only, you'll also need really good filtration to convert waste in the water and large, regular water changes to remove excess nitrates.

 

[RickyV]

Keeping the lighting on the lower side would be the first thing I'd do. I personally don't like reducing the photoperiod but that is another potential tool. I would also design the hardscape with a lot of dark/shadowy areas. I try shading the front display panel if possible. Also plenty of algae eaters. Next I'd grow as many emersed plants as possible. Can be grown in the tank, sump, or separate but connected container. I grow mine in a a mini above sump. But given this is brackish you may be limited here. So the next best thing would be a big algae scrubber.

I'm sure there is also chemical filtration that would reduce nutrients, but I feel plants/algae are easier with less maintenance. I bet a large wet dry filter would help too, the bacteria may compete with the algae. Something I've been thinking about trying is daily H202 dosing to reduce algae, but not sure how effective it'd be.

 

[John Troy]

Minimal lighting and lots of algae removal when it appears. As it's fish only, you'll also need really good filtration to convert waste in the water and large, regular water changes to remove excess nitrates.

OKay then so just the basics

 

[John Troy]

Yeah i'm thinking of doing something likes this from tank tested but with a figure 8 puffer. I think I'll just stick to lower photo-period and very weak lighting and a lot of scrubbing then, I'll see if there's any terrestrial plants that do well in brackish water. H202 dosing sounds interesting, given im not using any plants its more feasible but im sure pufferfish are more sensitive to it than most other species given they lack scales. Otherwise I'll look into some chemical filtration. Luckily a bit of algae will probably add to the aesthetic of a setup like this but I still want to mitigate it. Something I was wondering about was the possibility of recirculating RO water back through the system but Im not sure if this would work given how rejection rates work?

 

[Tyko_N]

I'll see if there's any terrestrial plants that do well in brackish water

Samolus valerandi is supposed to be quite tolerant if grown emersed, otherwise there's always mangrove if you have the space. Depending on the salinity some marine macroalgae could also work (like Chaetomorpha linum) and are great at soaking up nutrients. I'm not sure how nippy figure 8s are, but adding some algae munching mollies might be possible? (Wild-coloured sailfins are a sight to behold in themselves too)

 

[John Troy]

Samolus valerandi is supposed to be quite tolerant if grown emersed, otherwise there's always mangrove if you have the space. Depending on the salinity some marine macroalgae could also work (like Chaetomorpha linum) and are great at soaking up nutrients. I'm not sure how nippy figure 8s are, but adding some algae munching mollies might be possible? (Wild-coloured sailfins are a sight to behold in themselves too)

Yeah I'm trying to avoid too much greenery but I might research if there's any non-unsightly looking marine algae, yeah figure 8s tend to be quite nippy but a mangrove isnt a bad idea.