Refugium To Display Ratio + General Questions

[Teebo]

I have been long picking at this "lower maintenance" specific setup using a 16G display over an 8G refugium. That means the refugium makes up 1/3 of the total system volume. I am heavily into the art of FW aquascaping so I am confident I can pull off an amazing looking planted SW tank (aka refugium). This is all about nutrient export and water quality, well lit on a night cycle to help with pH consistency. I know some use a method of breaking up the light in smaller cycles to prevent algae from peaking in FW but this may screw up coral growth since they rely on internal algae. If anyone does not know what I am talking about my LFS uses it on their FW display...4 hours on, 4 hours off, 4 hours on, 12 hours off. 

 

The small tank is actually 8.5G it has 3 of the same dimensions as a 10G here it is next to one. I need as much of the space in this for display as possible so the return pump will be in a central weir tower with a heater that heats both tanks (same system). Have not figured out my mechanical filtration method yet, but I will not use a skimmer. It will be a really clean setup if I can only figure out how to insert mechanical filtration into the loop...I have a few ideas. 

[Muraki]

50% of my system volume is a refugium. Lets just say, I have not done a water change in over a year. But between the macro and coraline algae, I have to dose a good bit even though I do not keep many hard corals. I see great success ahead in your adventures with this setup. : )

 

 

[Teebo]

Thank you, if I use large (very large) mangrove trees would you try keeping them in the refugium for pH reasons or in the main display for more head room? I figured keeping everything that consumes nitrates in the bottom it will help stabilize pH during the reverse lighting cycle. Do coral photosynthesis like the mangrove would? If so I should try keeping them in the bottom to balance out the amount of photosynthesis occurring in both tanks?

[Clown79]

Mangrove placement is personal choice.

Many put them in their display, some in their aio chambers, some in the refugium.

[Muraki]

Personally Opinion, unless you have a setup specifically designed around mangroves, they don't do as much as a mixed macro display sump would. Using Macro's such as Caulerpa's, Blue Ochtodes, and other Red algae. I have had the best luck with C. prolifera, Never had any go sexual with my minimal maintenance schedule. C. sertulariodes and C. racemosa did very well for me as well, but did end up going sexual in my tank eventually. But never did any damage and between my skimmer and filter sock, cleared up in a day without a water change. 

[Teebo]

16 hours ago, Muraki said:

they don't do as much as a mixed macro display sump would. Using Macro's such as Caulerpa's, Blue Ochtodes, and other Red algae.

 

This is a powerful statement for me that backs up what I was leaning toward.

 

The amount of nutrient uptake I believe is what determines how much it can effect the pH right? I will keep my Mangroves in the display than, I can literally walk into my backyard and grab a Bonsai looking Mangrove. Depending on how dense of a Mangrove I grab it may compete with the macro algae no? I really do not have much headroom down there anyway. 

[Muraki]

Sorry for the delay in response. Been out of town. From the little I know of mangroves, they get fairly large, In a system of that size, I do not for see the mangrove being starved out by the other macro's, just slow its growth. I feel like you would have more gardening work between the macro's themselves to stop them from starving one another, or shading one another to the point of stunting the growth. I tried to keep a Macro display section in my sump, but in the long run, I got lazy and it became a battle between Chaeto and Caulerpa. I had some Caulerpa go sexual, probably from the chaeto choking it out of nutrients and light, but again, this is only a guess. I have had so much random macro come and go at this point. I thought I lost all my Blue Octhodes, but magically they reappear randomly, same with other's. For the most part I have gone to using Chaeto only, the thick and Thin varients. So far the Thick appears to be the easier and cleanest aesthetically. I used Mangroves in the past, they grew without issues, but between space and my limited pruning, they just weren't for me. I vote if you keep one, definitely do it in the display, I am sure you can work its root system into the design to look phenomenal. I've seen systems that are designed around Mangroves, and I have always loved them. A lot of what I suggest or say, is personal opinion from what I have tried. We learn from trial and error, so go have some fun.

 

As for the pH, I don't for see any issues specially if you can use the majority of that fuge space for macro, I keep macro in both my sump and display. Used to keep more in my display, but the turbo's ate nearly all of it, and I removed the Blue Ochtodes because I had a different algae issue to remove, and it in bedded itself into the Ochtodes, otherwise I would still have it in my display. Overall, Just have to find that happy medium with the amount of macro to the amount of fish/inverts in the tank to keep the nutrient levels and nitrates where you want them. I have to feed daily, if not twice a day. I have not had Nitrates read higher than 0 on an API test kit in the last 18 months with zero water changes. I probably need to get a salifert or Red sea kit since they can read lower, but I am just to lazy. pH and Nitrates will be the least of your concerns. Ca, KH, and Mg will be all you would have to actively monitor.

[Teebo]

Thank you for your response!

I think what my question comes down to now is the balancing of pH/photosynthesis. Too bad I do not have a way of actively measuring this. I am unsure how much photosynthesis occurs in general with the corals internal algae. The goal of many is to not only export nutrients but to use reverse lighting to keep a constant photosynthesis = smaller pH swing. Inch for inch I am curious "how much" photosynthesis occurs between corals and micro-algae, if corals photosynthesis twice as much per inch in theory you would need a refugium twice the size of your display to keep the most consistent pH. In this theory adding Mangroves no matter how slow their growth is contributing to the high level of display photosynthesis occurring. However, with the leaves being above the water I am not sure there is any "water column photosynthesis" occurring, just strictly nutrient uptake where the micro-algae has green surface area in the water column. 

I come from a very balanced freshwater background, so balancing my SW system is a goal and also why a display refugium is a must-extension of the SW hobby for me. I will deff be designing a tank based around Mangroves.  

[Muraki]

Makes sense. I have never looked into it with that much detail. If you would like, since I have a similar setup / ratio you are aiming for, I can test the pH in any time increments you like.