How much live rock for macro algae tank

[Landia]

Hi All, being a planted tank hobbyist, I'm drawn to macro algae tanks, examples of which I'll link below. This will be my first big jump into salt water.

 

Noticed that the macro algae hobbyists mention that the macro algae does most the filtering. Was curious how much lbs/gallon of live rock would be needed for a macro algae tank. Seem like very little according to the last video. Tigahboy is a hero!

 

 

 

[growsomething]

Not my area, very few ppl do macro only tanks.  I would think it all depends on your livestock, but very little rock sounds right to me, too.  Good luck!

[seabass]

Depends on the bio-load.  Sand has a lot of surface area, which helps.  The macroalgae itself probably provides surface area for nitrifying bacteria.

 

If there are more fish, I'd be tempted to run a sump with additional live rock or bio-media.  That way you can keep less in the display.  However, many fish still like places to hide, so some rock in the display is usually good.

[Landia]

My understanding from planted tanks and the videos above regarding macro algae is the the macro algae "sucks up" the nitrates and phosphates. Perhaps ask Tigah Boy his experience.

 

Dunno if I answered my own question but, this just in, According to bulk reef supply about macro algae tanks:

 

Choose enough rock to build whatever kind of scape you're looking for with anywhere from 0.5 - 1.5 lbs per gallon being the norm. ¹

 

 

Bibliography

 

Farnsworth, Robert. “Choosing Aquarium Equipment, Rock, and Sand. - Macro Algae Reef Tank Build EP: 2.” Bulk Reef Supply, Bulk Reef Supply, 24 Sept. 2021, https://tinyurl.com/3yj2vush.

 

Here is the long link if care to check out:

 

https://www.bulkreefsupply.com/content/post/macro-algae-tank-build-episode-2-rock-sand-equipment#:~:text=Choose enough rock to build,up with too much rock.

[seabass]

5 hours ago, Landia said:

My understanding from planted tanks and the videos above regarding macro algae is the the macro algae "sucks up" the nitrates and phosphates. Perhaps ask Tigah Boy his experience.

 

Dunno if I answered my own question but, this just in, According to bulk reef supply about macro algae tanks:

 

Choose enough rock to build whatever kind of scape you're looking for with anywhere from 0.5 - 1.5 lbs per gallon being the norm. ¹

Macroalgae does uptake nutrients, but that shouldn't necessarily affect how much rock you need.  You'll likely need to dose nutrients and even trace elements in order to keep the algae growing.

 

I believe that is BRS's normal range for marine tanks in general.  We used to suggest around a pound of rock per gallon of water, but have found that depending on the bio-load (basically the number of fish) that you might be able to get away with about half of that.  There's really no upper limit to the amount of rock except available space.

 

We're mostly talking about the biofilter here, so the rock doesn't even need to be in the display tank (a sump would accomplish the same thing).  However, care should be given to provide the fish with a suitable environment (caves, overhangs, open swimming areas, etc).  Although some fish might feel at home amongst the algae.

 

If using even less rock, additional bio-media should be used to ensure that your tank can support enough nitrifying bacteria to process all of the ammonia.  For a macroalgae tank, I'd probably recommend keeping the number of fish relatively low and using around a half pound of rock per gallon of water.

[ubpr]

Just enough for good looks. If you used to low tech or no tech FW planted tanks, this is similar: some hardscaping, some substrate, some plants. No any "per gallon" rule. Nitrifying bacteria live on all available surfaces. And don't put there more nutrients than tank is able to process, basics.

 

More bothersome part would be testing for elements and daily  dosing, iron and potassium tests are not cheap. It's interesting to do for a week, but after some months and busy schedule one starts look for other alternatives.