is this ok for macro algae?

I'd personally think that, in a heavily planted lion tank, if there were anything to supplement it would be iron.

 

I'm not sure I know what you mean.

 

Iron is a trace element, and there won't be significant amounts added to the tank through normal feedings and water changes, but is needed by macros in decent quantity to grow. Nitrate and phosphate would be added sufficiently by the lions, which gives them the ability to use the light and grow; but without extra iron, you're making that the limiting factor in the growth of the macro.

So, if there were anything to supplement in a tank with macros and lions, it would be iron.

 

I have never dosed iron and I have had great results with my macro growth. Some of these original mother plants are over 10 years old. From personal experience, you don't have to supplement your macros to get good growth. Especially with the non-demanding macros the OP has in mind.... caulerpas do not need encouragement to grow. The others are very hardy and definitely do not require supplementation.... except I don't know the scientific name for Oar grass, so I'm not sure what that is. The amount of Iron macro needs in minimal and the water changes will be adequate. That's unless you are planning on a wall-to-wall planted macro tank....

I have pictures of all my macros if you would like to see them.

 

We always want to see pics, especially of thriving specimens.

 

KK... My seahorse tank....

 

That is gorgeous

 

I have 13 tanks and could fill up this thread.... but that wouldn't be polite. More than many of the other "fish groups", seahorses people keep a lot of macros. I think that's how I came to use them in all my tanks.

 

You start your own show off your tank thread(s).

 

I always feel weird coming into a new forum throwing my pics up everywhere.