View Full Version : Looking for advice

09/02/2016, 01:11 PM
I have been in the aquarium hobby for about 50 years and have done just about everything there is to do in the hobby. I've been successful with planted freshwater tanks, reef tanks, fish only tanks, cichlids... you name it..... except for one thing.... marine macroalgae. I've tried it a couple of times only to face dismal failure and disappointment. I have tried to research techniques but, frankly, there is little that is useful and lots that is contradictory. It is now me versus it!!! Time to climb that last mountain of the hobby, my personal Mt Everest. I thought I would ask those who have been successful. So, a few questions...

1. Lighting. I have used lights I used for my reef (lots of blue!) without success. Should I go more with what I would use on a freshwater planted tank (Lots of red)? In other words, what lighting spectrum is best for this application

2. Substrate. I used aragonite. That seemed most appropriate. Can't imagine why I would use anything different. But might as well ask.

3. Filtration. Protein skimmer, yes or no? Sump system or would a canister filter work better.

4. CO2? Works for planted freshwater. But for macroalgae? Seems "wrong".

5. Live rock? I wonder if the denitrification would be a bad thing.

6. Fertilization or other additives?

I know it is a lot of questions and I could search the forums and get lots of different answers. But I'm looking for the winning combination others have used.

09/02/2016, 04:11 PM
Lighting with more yellow and red is better for plants, somewhere in the 5500k to the 10k spectrum. About 3-4 watts per gallon is good, and I find that macro grows faster under very bright light.

Unless you are going to get into seagrass, I see no reason to change your substrate. Some caulerpas like caulerpa prolifera can be put in the sandbed, and the substrate doesn't really matter for them. I have some caulerpa growing in a mix of oolite and crushed coral right now.

No, you don't need a skimmer. Marine macros will grow fast, and will suck up nutrients. A skimmer would remove nutrients from the water, making it harder for macro to grow.

You can run CO2. Marine plants and freshwater plants both utilize photosynthesis, which requires CO2. It will just help the macro grow faster. Just watch your pH.

You should have live rock. Live rock doesn't denitrify, the bacteria on it turns ammonia into nitrate. Macro should suck up some of the ammonia, but I am not sure how ammonia consumption rates compare to nitrate consumption rates. Live rock also offers places to put your macros, places for fish to hide, and places for biodiversity to grow.

There are a ton of fertilization/nutrient addition methods. The flourish line of products by Seachem works well, and some people add KNO3 (potassium nitrate) to their macro tanks to boost growth. The macro uptakes the nitrate quickly to grow, and potassium helps everything also. If you go through the links in the stickies at the top of the page, there are some useful write-ups about different nutrients to add.

Hope this helped, if you have any other questions, just ask :).

09/02/2016, 06:38 PM
How about filtration? Canister filter?

So far what you describe, with the exception of substrate, which makes perfect sense, is pretty much a freshwater planted tank type system. Maybe more water movement based on what I have managed to read. But otherwise similar.

09/02/2016, 07:59 PM
Your macroalgae is your filtration. My tank is running with nothing but macro and rock, and it is around 5ppm nitrate. I personally wouldn't put a canister filter on it, because the media you put in it would take away nutrients from the macro, which they need to grow.

Michael Hoaster
09/02/2016, 10:24 PM
A canister filter can be a helpful multi-reactor, with the right media.

I run CO2 through my canister filter, with calcium carbonate media, Bio-pellets and bio balls, supplementing CO2, calcium, bacteria and nitrate. The bacteria's for the filter feeders, everything else is for the plants.

cHRoNzZe 619
09/09/2016, 04:13 AM
How big of a tank you planning of setting up? Also blue light don't do much for algaes you needs more whites on... I usally recommend getting one of those Chinese led fixtures for macro tanks,plus for about 100$ you can get what you need from the light and they are dimmable,for lighting I have a 32in reefbreeder over my macro tank I never turn on the blues more then 15/20 percent ,whites 75 percent
Live rock is a MUST... Has a lot of bacteria and critters you need to help support your tank,everytime I start a new tank I always try to get live rock from members tanks to help boost Other rocks in the new tank,I usally don't go threw the algae blooms as most people do when first setting up a new tank.plus live rock gives your tank it's personality.
Substrate should be fine maybe toss In a small bag of fine sand and mix it a bit to have a variety of sand ..IMO your fine on the sub.
Never done CO2 so I can't saying anything about that..
Additives depends on the algaes you want to keep lately I have been adding calcium and raising my magnesium which I have never done just to keep my some algaes alive.