Experimenting with Specialty Refugiums

Zhubbell · Mar 7, 2021

Okay, so:
Water is pumped from my sump, and sprayed over the exposed substrate, where mangroves, and hopefully eventually some “ocean asparagus” (if I can find some) will be planted.

Note: I have considered having this pump shut off for certain times to mimic low tide. Any potential negatives? Any thoughts on the correct times/duration for this?

Then it seeps out, to the shallow water, slow moving, classic macro algae refugium.
Floss is in there to hopefully fill with pods to supplement my target mandarins diet in the wb15 next door. Right now I’ve got more pods then he can eat, but I know he’ll catch up.

The lighting is 2 retrofit 36” t5s, geismann grow bulbs. Wish I had done 4x24” instead.
Right now I have it on 24 hours. Also considered turning it off for maybe just 3-6 hour mid day? Thoughts on this? I have it mounted really high because I want to grow a tree, but I feel like the macros could use more light. Am I too “coral” mindset worrying about how much light in this case, or should I add a kessil refugium LED hanging down from the hood or something?

any overall comments? I feel like the exposed substrate is really going to provide an awesome component to the bacteria culture & complexity of life cycles happening in the tank.

does anyone else think this is as cool as I do, is it just me?
My wife thinks it’s just me.... well Me and my brother.

TexanCanuck · Mar 8, 2021

I agree ... it's definitely cool!

Couple of thoughts:

- While I agree that the exposed substrate will add a valuable habitat for bacteria, I'm not sure about the "low tide" simulation ... I know that's how the real world works but the real world also has a lot more biodiversity, volume, and other factors we haven't really understood yet ... not sure how this will "promote" biodiversity. But then again, that's not my area of expertise

- Mangroves are VERY slow growing. So while eventually that light may have to be that high, it certainly doesn't for the foreseeable future. Instead of investing in more lights, I'd suggest lowering the fixture for now. The mangrove won't suddenly sprout overnight!

- 24 hour lighting cycle is not good for either the macros or the mangrove. All of them need a chance to respire. I'd suggest a more natural lighting cycle for the mangrove - it is a legitimate tree with a vascular system that needs to follow a diurnal cycle.

- Other than providing a really cool environment in your home, how will you now your approach is actually "working"? Are you judging it by how much nutrient export it is facilitating? Or is it purely for aesthetics? I ask only because while they are definitely cool, mangroves are not very effective at nutrient export (since they are such slow growers). So if nutrient export is your primary measure of success, you may need to load up on them!

Anyway ... despite all of the above, I think your wife is wrong ... it's definitely cool.

Zhubbell · Mar 8, 2021

TexanCanuck said:
I agree ... it's definitely cool!

Couple of thoughts:

- While I agree that the exposed substrate will add a valuable habitat for bacteria, I'm not sure about the "low tide" simulation ... I know that's how the real world works but the real world also has a lot more biodiversity, volume, and other factors we haven't really understood yet ... not sure how this will "promote" biodiversity. But then again, that's not my area of expertise

- Mangroves are VERY slow growing. So while eventually that light may have to be that high, it certainly doesn't for the foreseeable future. Instead of investing in more lights, I'd suggest lowering the fixture for now. The mangrove won't suddenly sprout overnight!

- 24 hour lighting cycle is not good for either the macros or the mangrove. All of them need a chance to respire. I'd suggest a more natural lighting cycle for the mangrove - it is a legitimate tree with a vascular system that needs to follow a diurnal cycle.

- Other than providing a really cool environment in your home, how will you now your approach is actually "working"? Are you judging it by how much nutrient export it is facilitating? Or is it purely for aesthetics? I ask only because while they are definitely cool, mangroves are not very effective at nutrient export (since they are such slow growers). So if nutrient export is your primary measure of success, you may need to load up on them!

Anyway ... despite all of the above, I think your wife is wrong ... it's definitely cool.

1. So the “Tide Pool” is something that I had done before.. I had an 18” cube tank, with a 12” cube display tidepool next to it. It had two drain lines, one halfway up the back, and one at the “high tide water level” (full).
The ball valve on the lower drain line was closed most of the way so it didn’t drain too quickly during high tide and then when the pulps would shut off, the water would slowly drain, power heads stay on. Had sally light foots that would play on the exposed rock and such, and lead to some really interesting growth on the rocks. Not sure what “good” it did, maybe just perceived? My main point with that was thinking that the mangrove would be healthier if the higher roots dried out a bit a couple times a day. My understanding is that mangroves have “wet roots” and “dry roots” that do different things, the dry roots obviously get wet, but aren’t wet all the time. Seemed to me that this would make for a healthier Mangrove. But that’s all just assumption. I agree the algae below wouldn’t be benefited by it, except I guess that it would allow a time when I could dose alittle phosphate or whatever to them, give them time to use at least some of it up before dumping it into the main water column?
2. True..
3. So would you do same schedule as reefs or opposite? With the light spill I’m thinking same, but with the pH I’m thinking opposite.
4. Nutrient export, bacteria space, etc are all the point, originally the idea was just fill the sump with rock and whatever like I normally would but the more I thought about it,‘I’m going to have 4-5 vectra pulps in there, a big huge skimmer, etc, I am better off keeping that area cleaner and keeping the light on a seperate tank. And right now, my phosphates and nitrates are alittle high, looking to combat that, and stop nuisance algae growth, which isn’t out of control, but a constant annoyance.
I have ulva, chaeto and caulerpa currently in the shallow macro area, so I think that will be the “main nutrient export” area, while the mangrove crate will be decorative, as well as focus on the bacteria that will cultivate that substrate.

Zhubbell · Apr 1, 2021

about a month in, and it’s looking pretty awesome. I have 5 different macros in there now, plus the mangrove looking awesome, pretty sure the other mangrove was dead when I put it in, but thought I’d see if it wouldn’t surprise me.
Display tank seems to have some less nuisance algae growth, but I think that’ll ramp up here soon.
Also thinking a small powerhead In the macro zone might be beneficial.

Zhubbell · Jul 8, 2021

Starting to grow pretty nice.
I’m going to start paying more attention to my phosphates.
Right now I’m ranging between 0.18 and 0.85 probably.
Where is the sweet spot do you guys find? Should I run the system lower and then close it off from the rest of the tank one day a week and dose phosphates heavy or something?
Still have to move the light lower but I lost my drill bit fir the tap con screws I got and I keep forgetting to grab one at Home Depot.

Mr Fishface · Jul 9, 2021

Looks really good! Phosphates are good to have but I wouldn't worry unless they basically drop to 0 or unreadable levels. With algae I found the available nitrogen to be bigger issue myself. Can't wait to see how this turns out though. I've always wanted to try a mangrove.

Dolphins18 · Jul 9, 2021

I've got a few mangroves, 2 were touching the light after one year, started burning the leaves lol. They are in a new tank and it is open on the ground, I am putting lights on the ceiling next week. I'd like them to grow up very high as the tank is in the corner in an indoor/outdoor area.
Another one growing much slower has planted it's root structure into the rock.
They definitely like dirtier water, I only keep them in nem tanks.
I'd be really curious what happens if you try the low tide idea. Really cool.

Ichtha_yo Stuff · Jul 9, 2021

Here is a video explaining my tidal simulation with mangroves.

Zhubbell · Jul 9, 2021

Ichtha_yo Stuff said:
Here is a video explaining my tidal simulation with mangroves.

Very cool - I did a version of this years ago with my brother. We built him and 18” cube tank, with a sump below and then a 12” cube next to it. The 12” cube had a timer on the return that ran on a timer and shut off for low tide. It has two drains, on near the top and one turned way down on the ball valve that was only like 6” up the back side of the tank.
Same effect.
I loved it - we had sally light foots crawling around, a ton of rock work that would be exposed during low tide - it was really cool!

Zhubbell · Jul 10, 2021

Mr Fishface said:
Looks really good! Phosphates are good to have but I wouldn't worry unless they basically drop to 0 or unreadable levels. With algae I found the available nitrogen to be bigger issue myself. Can't wait to see how this turns out though. I've always wanted to try a mangrove.

What is the correlation between nitrates and nitrogen?
I am running between 2.75 and 5.00 nitrates, but attempting to lower that a bit, or at least keep it more regularly on the lower end of that.
I just added one of the brightwells Export Bio Plate that I seeded with MicroBacter7 to my sump.

Subsea · Jul 11, 2021

Zhubbell said:
What is the correlation between nitrates and nitrogen?
I am running between 2.75 and 5.00 nitrates, but attempting to lower that a bit, or at least keep it more regularly on the lower end of that.
I just added one of the brightwells Export Bio Plate that I seeded with MicroBacter7 to my sump.

While there is a fixed ratio of N

in biomass of macro and I assume mangroves, don’t assume the water needs to be in that same ratio. First off, your mangroves gets its nutrients from roots in substrate which will not be the same chemistry as the water column. With respect to macroalga, the average ratio of N

is 30:1, some as high as 100:1. However, it is not necessary to chase those numbers, it is only necessary to have sufficient quantity to allow uptake.