New Setup -- Buncha questions

[BonesCJ]

After being out of saltwater for a while I'm setting back up my 90 as a Macroalgae tank and have some questions as well as want to double check my planned setup. Please feel free to critique any of my ideas.

90 gallon system
20 long sump
mag 5 return (probably throttle it down to 2/3)
2 Koralia Evo 750's on a controller
2 Kessil a160we's with controller
planning to go skimmerless, I do have a mechanical filter I can always use if needed.

1've got 50 lbs of marco rock coming this week and plan to build a single coral head for fish to use and I'll add some regular Live rock to seed. Going to leave plenty of open sand room.

going to have at least a 1-2 inch sand bed using Caribsea reef grade

Right now the system is empty except for tap water running as a mechanical test of all the seals, so far so good. Sand/rock/salt all arriving this week, hoping to get the tank properly running this weekend. After about a week for the salinity to stabilize I plan to added some proper Live Rock and maybe a half dozen mollies to get the cycle started.

My biggest question is when to add the macros vs when to add fish? In a freshwater planted tank you can start plants immediately and they often help with the cycle but macros seem to be a bit more temperamental. I can run the system with a standard LED strip light for awhile to keep microalgae growth down during the cycle but would like to get at least some macros in there sooner rather than later.

Any thoughts on this setup or the timeline?

 

[Michael Hoaster]

This sounds like a great tank in the making!

As for when to add fish v macros, it's up to you. From my experience with a similar kind of tank, I'd recommend you add both at the same time. I added a bunch of macros and seagrass right at the start, a la fresh water planted tanks. The idea was to get the plants in place before fish, to outcompete algae. But without fish, the tank was so nutrient poor, the macros gradually withered away. After I added fish, macros started popping up. These plants really do need plenty of nutrients to thrive. In planted tanks bacterial filtration is much less important than with a tank containing no plants.

With a new tank, you are dealing with massive bacterial colonization, which competes with the macros for nutrients. I think your idea of adding mollies is a good one. I'd also get some snails in there. But you don't have to feed either of them, as they will have micro algae to eat, so you may want to add some fish you have to feed, and feed a little extra for the plants.

Or you could cycle the tank in dim light for a month or two, then add plants. This will simplify your situation. Rather than cycling and trying to establish plants at the same time, you would be doing it one thing at a time. But who has the patience to do that!