My Complex Refugium System

[philaquarist]

Hi,

I am a 50+ year old aquarist from the Philippines. I’ve been keeping marine tanks since 1970, and have gone through most everything in this hobby. Perhaps my experience has been a bit diluted by the financial limitations of living (and earning a salary) in a third world economy, but on the other hand, it has also been enhanced by easy access to reefs and other marine habitats.

I’m about to start building my “dream” system of a 500+ gallon system of 6 display tanks (each representing a different biotope), but sharing a common water management system. A key part of the design is the presence of a fairly complex stand-alone upstream refugium system.

This fuge is not designed to achieve nitrification/denitrification (a large 50-gallon RDSB will help me there). Instead, the major objectives of the refugium are essentially:
1) biodiversity
2) added food-webs (mainly planktonic larvae of the various fuge creatures)
3) nutrient export (through Chaetomorpha)
4) added water mediation/filtration (through various filter-feeding livestock)

The basic refugium design had been floating in my mind for several years now, so I am naturally very excited at being so close to finally implementing it. Since the start of 2008, I have sent design prototypes to a few friends for private comments and suggestions. These include some hobbyists from the Philippines, Japan and the USA (including a few who are members of this forum), as well as the senior marine biologists from the top universities in my country. Their comments have brought me to the design that I have so far.

I am enclosing some very broad design specifications for this refugium (see attached pdf), hoping that some good folks in this forum will see both the forest and the trees, and give me further comments, criticism and suggestions. I hope to elicit both big-picture comments, as well as very detailed suggestionsm whether on design or on biotope/livestock selection.

Any comments will be very timely. My schedule calls for all tanks to be finished by mid-December, cycled by mid-March, and slowly populated starting April. (Much of the old livestock from my old 2x90-gallon systems have been given away for adoption, while some were kept in my still-existing 350-gallon marine grow-out pond, so I would need to slowly gather new specimens).

Thanks in advance. And if anybody needs anything on the hobby in the Philippines, just give me a quick PM or email. I will try my best to answer or help you. (Being "the" pioneer / old-timer has its advantages )

Phil

 

[tonyespinoza]

enjoyed reading your design...

i'm a big fan of the same set of principles and am building a multi-fuge system myself.

in my own experience (far more limited than yours!) i have found reef keeping to be a weird blend of planning, knowledge and awareness of what's actually developing in our tanks. in other words, all the planning in the world is no substitute for paying attention to a particular system and being flexible enough to adapt.

so i guess, my only 2 cents would be to figure out how you maximize flexibility and allow for tuning. with so many detailed intra-refugium relationships to balance i would worry that it might be hard to observe and measure what is and isn't working. granted, there's an opportunity that it will all snap together and work perfectly -- but it seems more likely that some theories won't pan out as well as others. perhaps you could bet on a subset of the ideas and start with those first choosing to expand or contract various chambers based on what's working.

i think i'm going to try for a simpler setup myself. my display is shallow and wide (60" x 40" x 20") and i'm going to minimize rock and focus on SPS in a high flow environment. my sump will feed a high flow bare bottom live rock tank with no lighting, a large chaeto refugium, and a smaller low flow, no light zone.

my concern with an RDSB is that since i won't be keeping many fish, the uptake of N out of balance with P uptake might skew the environment too far towards the nutrient poor end of the spectrum in an unbalanced way. as i understand it the chaeto should export N and P in balanced proportions.

 

[TheH]

Rather than placing rocks in section K in an attempt to block light incoming from the overflow, just make the overflow opaque. Or make it opaque in addition to adding the rocks.

 

[philaquarist]

<a href=showthread.php?s=&postid=13723196#post13723196 target=_blank>Originally posted</a> by tonyespinoza
in my own experience (far more limited than yours!) i have found reef keeping to be a weird blend of planning, knowledge and awareness of what's actually developing in our tanks. in other words, all the planning in the world is no substitute for paying attention to a particular system and being flexible enough to adapt.

so i guess, my only 2 cents would be to figure out how you maximize flexibility and allow for tuning. with so many detailed intra-refugium relationships to balance i would worry that it might be hard to observe and measure what is and isn't working. granted, there's an opportunity that it will all snap together and work perfectly -- but it seems more likely that some theories won't pan out as well as others. perhaps you could bet on a subset of the ideas and start with those first choosing to expand or contract various chambers based on what's working.

tonyespinoza,

Thanks for the input. I whole-heartedly agree, in our hobby, somehow things always find a way of deviating from what we plan or expect

A marine biology professor warned me that with the relatively "porous" boundaries between biotopes, its possible that (over time) one or more dominant species will emerge, and rule all the chambers! Then all those intricate boundaries will just be a waste of time, and I would be left with essentially just an overly-fancy Chaetomorpha raceway and lots of sand beds in various chambers dominated by the same in-fauna.

But I'm hoping that with different substrate sizes, somehow different subsets of in-fauna will naturally proliferate. My other consolation is that I am within driving distance to very good seagrass meadows, reef shallows, etc, so I have an easier chance to repopulate the fuge (or selected portions thereof) in case such "speciation" occurs.

But certainly I will follow your advice: adjust and improvise when things don't turn out as planned

<a href=showthread.php?s=&postid=13723196#post13723196 target=_blank>Originally posted</a> by tonyespinoza
i think i'm going to try for a simpler setup myself. my display is shallow and wide (60" x 40" x 20") and i'm going to minimize rock and focus on SPS in a high flow environment. my sump will feed a high flow bare bottom live rock tank with no lighting, a large chaeto refugium, and a smaller low flow, no light zone.

Good luck as well on this project. I hope you will find as much excitement in the visualization, planning and design, as much as I did with mine.

<a href=showthread.php?s=&postid=13723196#post13723196 target=_blank>Originally posted</a> by tonyespinoza
my concern with an RDSB is that since i won't be keeping many fish, the uptake of N out of balance with P uptake might skew the environment too far towards the nutrient poor end of the spectrum in an unbalanced way. as i understand it the chaeto should export N and P in balanced proportions.

I presume you're talking of the Redfield ratio. Yes, I am also sensitive to that potential problem. But in my case, knowing my history and accepting my sloppy husbandry (and my tendency to overstock), I've never been able to reach (almost) zero nutrients (whether N or P) in my tanks. So if that problem comes, it would be a new (and pleasant?) one for me to have

Levity aside, I've also considered that possibility (about not enough N to do any more natural take-up of P). My thoughts were to have up to three small reactors for granular ferric oxide to absorb phosphates (I could activate one or more of them either regularly or temporarily as needed, depending on my tank conditions).

Another suggestion that I received (to counteract that specific N/P imbalance) was to dose nitrates (??!!), especially as one of my display tanks will be a seagrass-bed biotope, and another one will be a "planted tank" of various macro-algae (simulating the biotope of macroalgae-encrusted rocks, located before reaching the actual fringing coral reef). That's actually part of my challenge: some tanks require very low or zero nutrients, while other tanks clearly need some non-trivial level of N/P for growth, yet they share the same water system. Yup, we all must be "closet" masochists to dream up all these crazy stuff.....

Thanks again for the response,

Phil

 

[philaquarist]

<a href=showthread.php?s=&postid=13724384#post13724384 target=_blank>Originally posted</a> by TheH
Rather than placing rocks in section K in an attempt to block light incoming from the overflow, just make the overflow opaque. Or make it opaque in addition to adding the rocks.

Thanks for the simple but very effective suggestion. I may just yet do that, and get rid of Section K altogether (giving me slightly more room for the cryptic zone).

Right now though, my problem is that I cannot locally find any acceptable "opaque" glass or equivalent (to keep the cryptic zone light-free). My worst-case scenario is that I will paint black all the external sides of all the glass panes around Sections J, K, L and M, to keep everything dark. And then maybe I could just place some Matala mat (or any other seawater-safe opaque material) on the glass pane (the boundary between Section I and Sections J+K) to completely light-proof it.

Thanks again,

Phil

 

[cdness]

Impressive design... Very complicated but I hope it works out for you.

 

[salty joe]

I like your plan. Please keep us posted.

You might want to change the photoperiod on the Chaeto to 6 hr. on/6 hr. off. A guy here on RC used a 70 W HPS growth lamp with that photoperiod, and was exporting a volleyball size wad of chaeto weekly. He had two separate Chaeto chambers, each with a 70W HPS lamp. FWIW, his Chaeto did not tumble. When one chamber was lit, the other was dark. His PH was rock solid. This Chaeto study I found backs up this guys experience.

http://www.int-res.com/articles/meps/134/m134p207.pdf

I wonder if it would be worthwhile to add a tapered bottom to your fuge as a detritus trap and suspend everything above the tapered bottom. A valve could be installed at the bottom of the taper. This would be an easy way to change water and remove detritus.

Will you have any further filtration?

 

[philaquarist]

<a href=showthread.php?s=&postid=13731608#post13731608 target=_blank>Originally posted</a> by cdness
Impressive design... Very complicated but I hope it works out for you.

<a href=showthread.php?s=&postid=13738503#post13738503 target=_blank>Originally posted</a> by salty joe
I like your plan. Please keep us posted.

Thanks, cdness and salty joe.

<a href=showthread.php?s=&postid=13738503#post13738503 target=_blank>Originally posted</a> by salty joe
You might want to change the photoperiod on the Chaeto to 6 hr. on/6 hr. off. A guy here on RC used a 70 W HPS growth lamp with that photoperiod, and was exporting a volleyball size wad of chaeto weekly. He had two separate Chaeto chambers, each with a 70W HPS lamp. FWIW, his Chaeto did not tumble. When one chamber was lit, the other was dark. His PH was rock solid. This Chaeto study I found backs up this guys experience.

http://www.int-res.com/articles/meps/134/m134p207.pdf

So its essentially 6-on / 6-off / 6-on / 6-off every day? Thanks for the info. I will definitely explore and maybe experiment with that idea.

<a href=showthread.php?s=&postid=13738503#post13738503 target=_blank>Originally posted</a> by salty joe
I wonder if it would be worthwhile to add a tapered bottom to your fuge as a detritus trap and suspend everything above the tapered bottom. A valve could be installed at the bottom of the taper. This would be an easy way to change water and remove detritus.

Again, thanks for the idea. Now that you mention it, I remember seeing pictures in some old (1990’s?) books, where they had such tapered bottoms for easier clean-out of tank detritus. My space limitations will not allow me that tapered design. But I am now convinced that I should place an emergency drain in section B22 of the Chaetomorpha raceway, where the detritus will probably accumulate. I could then use this as a drain for emergency (or regular) clean-up, with detritus being drawn out by the outflow. Not as efficient as a tapered bottom drain, but probably sufficient for my needs. Thanks again for this great idea.

<a href=showthread.php?s=&postid=13738503#post13738503 target=_blank>Originally posted</a> by salty joe
Will you have any further filtration?

Yes, the refugium system is expected to help in the food-web creation, nutrient export and in water mediation. But the bulk of the system’s water treatment will really come from:
- 2 x Octopus Extreme 300 skimmers
- an old MacroAqua 300 needlewheel skimmer with ozone (a stand-by contingency feature which will automatically turn on only if ORP drops below 350mv, hopefully very seldom)
- a 50-gallon remote DSB for denitrification (Calfo-style)
- several fluidized reactors containing GFO (for phosphate control) and GAC (to remove gelbstoff and other excess organics)
- a sulfur denitrator (will only be implemented if I cannot bring nitrates down to zero in spite of all the above)

It might be a bit too much for a system of less than 600-gallons theoretical water volume, but the challenge is that I will keep two low-nutrient biotope tanks as well as four higher-nutrient ones, all sharing the same water system and all heavily stocked.

So right now, the concept is to have as much food flowing through the system (through frequent feeding, continuous phytoplankton drip, regular zooplankton creation, etc), but have enough skimming/filtration power to take out the resulting wastes and nutrients immediately. I've never had a zero-nutrient tank in my entire life, so I don’t really know if this design will work though .

Thanks,

Phil

 

[zygote2k]

Why not go entirely natural? The skimmers are a waste of money and nutrient in a system like this. All available nutrient will be absorbed by plantlife and other species. You're thinking about feeding nitrate while the skimmers are removing it- doesn't really make sense. They are totally un-needed. You could also use Dragons Breath algae as an alternate exporter. It grows as fast as Chaeto especially in a raceway set-up.

 

[joeypantangco]

that is one complicated set up.

 

[erics3000]

I like all the different zones....Cant wait to see you start...........

 

[WhatIgot]

I have seen powerpoints for junior mining companies that were less intensive.
I have no business trying to comment on someone who's mind obviously reaches beyond my owns ability to grasp the science behind this hobby, but I just wanted to say that I really admire you planning and attention to detail.

 

[freetareef]

i like it....

 

[freetareef]

i like it a lot...