NNR / phosphate/RDSB/Refugium etc.

Hi Folks,

Further to some research I have been doing into phosphate and nitrate reduction, I have come up with a few idea’s for modifying my system to help control these â€"œ this basically will involve:

1. A dedicated remote DSB for nitrate management, maintained in darkness, with pre-filtered (mechanical) water, and high flow â€"œ as per the “DSB in a bucket” thread.
2. A dedicated algae refugium for phosphate management. Apart from the macro, I am not sure about how this will be set up.
3. A dedicated equipment sump into which everything will drain (i.e. display, remote DSB and rfefugium)
4. A large RO and salt water make up storage tank(s).

What I wish to discuss is how best to set up each item individually, but primarily, how I should link it all together. I propose to locate all this in a dedicated room (a small shed, outside). Space will be tight, but it should be adequate (the biggest shed I can fit is 6’x6’.

I have 3 no. all glass tanks that can be used â€"œ 48”x18”x20”, 44”x18”x15”, 48”x12”x12”. I intend to use the first as the main sump, the second as the refugium, and the last as the DSB. DSB is the most simple, so I’ll start there:

DSB - 48”x12”x12”, bulkhead each end â€"œ ¾” in and 2” out, fill with 8” of aragonite sugar fine sand, with 2-3” of pre-filtered water flowing over it, hopefully quite rapidly. This is modelled on the example given in the “DSB in a bucket” thread i.e. the 55 gal tank for a 2,000 gal system.

Refugium. 44”x15”x18” illuminated with twin T5 lighting with reflectors (or similar). Obviously I will need some form of substrate to anchor the macro to….. I’ve got a 2 gallon bucket of “dead” LR rubble â€"œ that could be used â€"œ or would I be better off with sand and a few lumps of LR, for biodiversity etc.?

Sump â€"œ 48x18x20 â€"œ gonna do a basic arrangement here â€"œ waste water in, mechanical filter, then skimmer. Next chamber, pump to refugium and DSB. Also feeds to calcium reactor etc. Last chamber â€"œ returns from refugium, dsb, calcium, kalk, heaters etc and return pump to display.

My initial thoughts centre around position of the skimmer, RDSB and refugium. Skimmer first, remove as much as possible. The next bit is tricky. I have read that the two limiting factors for growth (hence nutrient export) for macro algae are phosphate and nitrate. That is to say in order for it to grow (and remove nitrate and phosphate) there needs to be a supply of BOTH. So, should the nitrate be totally depleted by some other means, then the macro will not grow, and if it does not grow it will not “harvest” the phosphate……… am I on the right track here? A further assumption is that if one pumps water through a remote DSB then the water leaving will have much less nitrate that the water entering. Putting these two assumptions together, does it follow on to say that it would not be suitable to fee the refugium with water from the DSB, is phosphate removal is the ultimate goal? i.e. perhaps it’s a better idea to feed the DSB with water from the refugium â€"œ but then you are introducing possible detritus i.e. its no longer “prefiltered” â€"œ for if you did you defeat half the purpose of the refugium (i.e. critters etc). So, should I look at pumping water to both the DSB AND the refugium separately? What kind of flow should I put through both?

Diagrams to follow â€"œ but I know people have tried this type of thing before â€"œ so thoughts and input please.

Regards,

Matt
 
Re: NNR / phosphate/RDSB/Refugium etc.

<a href=showthread.php?s=&postid=10301503#post10301503 target=_blank>Originally posted</a> by mattsilvester
Hi Folks,

Further to some research I have been doing into phosphate and nitrate reduction, I have come up with a few idea’s for modifying my system to help control these â€"œ this basically will involve:

12. A dedicated algae refugium for phosphate management. Apart from the macro, I am not sure about how this will be set up.
Regards,

Matt

Matt you are a long way form home my friend.:bum: fancy bumping into you stateside.
Think about the disadvantages of uses algae as part of your filter programme, the pH drop just before dawn cause the bohr effect in the fishes blood, not to mention gill lamanna ballooning late afternoon just think about the history when were using triclke filter in the early 80s certain parts of the wild west were still using under gravel filters, see you back on craggy island soon.:bum:
 
Well... since ya asked:

I'd have my main display tank drain directly into the macro algae tank. Macro algae does need nitrate, and if it soaks some of it that's not necessarily going to destroy the functionality of the RDSB.

In regards to the internal setup of the macro refugium, it depends on what we're trying to do here. If phosphate removal is the only function this refugium is meant to fufill, i suggest setting this tank as barebones as possible. The species of macro algae that are best at exporting phosphate need to tumble. Minimally, that requires an unobstructed directional flow. Depending on flow, live sand might be possible but it may also get pushed into pumps and filters, which probably isn't desirable. In this scenario you'd be best by going with cement or ceramic tile, or live rock. Personally, the cost of live rock might not be worth it. Tile eventually crusts over with coraline algae.
Now, If your desire is to facilitate biodiversity and promote some overlap in functionality, i suggest a slightly different setup. Flow isn't as important, and the species don't necesarily have to be kept tumbling. I'd do a thin Sand bed, not more then 3 in. (6-8 cm) deep and top it off with ceramic tile. Once again, live rock could be substituted, but it's an additionaly cost. 2-3 species of algae would be ideal. Don't get too crazy though. Like most things, macro algae has space requirements, and it's better to have extra room then not enough. Especially considering that macro growth is the method through which phosphate removal is accomplished.

After the macro refugium i'd drain into the sump.

I'd proably hook the RDSB up as a sort of peripherial. From the reading i've done, they occasionally need to be allowed to sit idle. While i have my opinion as to why this happens, i haven't been able to test any of of my theories. Suffice it to say, you need to occassionally take it offline.

I'd probably hook RO storage to directly to my sump, but it may be worth while to hook it up to your RDSB. Dosing the RO water through the RDSB seems like a good way to increase flow, if only temporarily. This idea might be too much work for too littel result though.

Anyway.... just some thoughts.
 
Qes. Can algae live well in an environment of 24/7 lights on?
In any case as phosphate resins are readily availble just like carbon, why not just run a resin instead?.
 
yes, algae will thrive under 24/7 lighting..... although recent discussion with some folks that have been doing it for years seem to prefer a short "lights out" period..... benefits are two fold - better algae growth hence better nutrient export, and if timed correctly (i.e. at the systems pH peak) it can further stabalise pH. So I think I will go with the latter - timing it so the lights go out from maybe 5 or 6 pm until 10 or 10.30pm..... lights go off in display at 11pm.

running resin - yeal I'll probably have to run that as well also..... but there are more benefits than phosphate absorbtion - I just want to maximise the amount it will absorb, and in doing so, it should (hopefully) provide maximum competetion against nuisance algaes.
 
I am planning on going along with almost the exact same setup. You can click on the little red house to see my sketchup plans for my setup. I also plan on having a refufgium, water change tank, RDSB, a frag tank and a large main sump for everything to drain into. Let me know if you see any faults in my planning.
 
Dear God thirschmann!!! that is some set up........

That is something to read tomorrow morning once I've clock into work!!!

look forward to it!
 
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