Macroalgae choice for refugium

[Mark Dunlap]

I'm considering bringing a refugium back online after many years without. Tank is 90 gallon currently FOWLR. Potential refugium is approx 15 gallon. What would be a good choice of macroalgae? Best to do a single species or a mix? Do some need a sand or mud substrate to root into?

 

[lapin]

it really depends on how good you are at growing them. For starters Ulva ( sea lettuce ) is hardy. Grows fast and it’s easy to remove the extra growth.

 

[penfold2]

I'd say just pick one that you like and try it. What works great for one person may not work as well for someone else. I started with Chaeto, but it didn't grow well for me, even when supplementing with ChaetoGro. I switched to Gracilaria parvispora and I harvest a couple big handfuls every two weeks on a 25g tank.

They can take a lot of light as well. The fuge compartments on my AIO have 12w lights mounted on the back glass, just a 1/4" from the macro on the other side. I'm pretty sure it's significantly more intense than my display lighting.

Also, Caulerpa will root into sand, but I don't think any of the commonly used macros require substrate. They can easily grow free floating.

 

[ThisIsTheWay]

As others have mentioned, you may need to experiment with a couple types to figure out what grows best in your system. I personally grow macroalgae in my displays (I have AIO tanks so no sump for fuge) and have had good luck with dragon's breath and acid rain (Not mine, but it looks like this: https://www.ebay.com/itm/297093544068). I tried gracilaria but it slowly withered away, could of been the specific variety.
I also have red string of pearls macro that I'm trying in a second tank and it seems to be doing well.
I have not tried chaeto or caulerpa so I can't comment on those.

A note on sea lettuce, I had a piece that did not do well and withered away. HOWEVER, it has now reappeared all over the tank wherever it has found favorable conditions. It's not excessive so I don't mind it and I know it provides some good variety for my cleanup crew. I bring it up though so that you're aware that if it doesn't like the refugium conditions and disappears, it may reappear in your main display if it likes those conditions better.

 

[Amstar]

for those that have macroalge in your sump - are you concerned/has it gotten from your sump to your main tank? How do you ensure that it doesn't

 

[vlangel]

for those that have macroalge in your sump - are you concerned/has it gotten from your sump to your main tank? How do you ensure that it doesn't

That's a valid consideration and not easy to ensure that the macro does not have pieces break off, get sucked into the return pump and end up in the display. Growing a macroalgae like Codium is more controllable. Pieces don't break off as readily nor do those pieces spread all over the place. It may not grow fast enough to take up nutrients in a satisfactory way. Its the macros that grow like wildfire that so effectively control nutrients. However, macros can so effectively reduce nutrients as to strip the water column of nutrients and that is not a good situation.

 

[penfold2]

for those that have macroalge in your sump - are you concerned/has it gotten from your sump to your main tank? How do you ensure that it doesn't

You can use macros that don't readily attach to substrates. Pieces of my Gracilaria parvispora occasionally make it into my display, but they've never taken hold. Cheato is also preferred by many for this reason. Macros like Caulerpa and Ulva though, have the potential to be more problematic in this respect.

 

[lapin]

If your uv light is inbetween the sump and the return to the main tank, this should prevent most migration.