!!!SPS SUCK! THE ACRO-FUGIUM WRITE UP!!! I guess I finally finished this thing, sort of
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robert
Valuable Member
Typically I add bentonite once a week when I flush my filteration or any time I see an increase in water particulates - dust like POC in the water column - or if I see any increase in algae stains arround my coral colonies. I use it fairly liberally - but not daily. Maybe twice a week on average.
I don't routinely test for anything except for sality and temperature. I ocassionally spot check nitrates, alk and calcium. I never test phosphate. More than anything, I watch my corals daily - if something that has been doing well - starts to decline - I look for pests first - allelopathy next - followed by signs of eutrophication - and if nothing - I'll look at the chemistry. If chemistry is constantly drifting - then I usually adjust my salt mix and water change - I rarely dose.
Thanks for the link - I rushed through it this morning - but I will read it closely this evening - looks promising.
I don't routinely test for anything except for sality and temperature. I ocassionally spot check nitrates, alk and calcium. I never test phosphate. More than anything, I watch my corals daily - if something that has been doing well - starts to decline - I look for pests first - allelopathy next - followed by signs of eutrophication - and if nothing - I'll look at the chemistry. If chemistry is constantly drifting - then I usually adjust my salt mix and water change - I rarely dose.
Thanks for the link - I rushed through it this morning - but I will read it closely this evening - looks promising.
robert
Valuable Member
@Thales - I had a chance to read the link you posted, but haven't had time to follow through on the citations yet. Very good article - quite alot to think about - and I have a couple of additional citations that would fit nicely with the context of the article.
I initiated and primarily use bentonite for its reputed ability to bind organics - phosphate binding was a secondary consideration as it was suggested that it would not be effective in saltwater. As I don't test for phosphate, I have to rely on the citation I give above in this respect.
Do you have a concern with the use of bentonite in our systems? I've used it long enough to feel quite confortable with its application - but would welcome any additional info regarding its use - even if speculative. I would also value any citation, opinion or otherwise with respect to my premise of low-carbon/low-bacteria reefing as I allude to in my posts earlier in this thread.
My present system grows little algae despite being heavily stocked with fish - light to moderate corals, small frags - and having relatively little in the way of rock (50-70lbs of man-made dead rock in a 450g system - no substrate) - I'm at a bit of a loss to explain why.
I initiated and primarily use bentonite for its reputed ability to bind organics - phosphate binding was a secondary consideration as it was suggested that it would not be effective in saltwater. As I don't test for phosphate, I have to rely on the citation I give above in this respect.
Do you have a concern with the use of bentonite in our systems? I've used it long enough to feel quite confortable with its application - but would welcome any additional info regarding its use - even if speculative. I would also value any citation, opinion or otherwise with respect to my premise of low-carbon/low-bacteria reefing as I allude to in my posts earlier in this thread.
My present system grows little algae despite being heavily stocked with fish - light to moderate corals, small frags - and having relatively little in the way of rock (50-70lbs of man-made dead rock in a 450g system - no substrate) - I'm at a bit of a loss to explain why.
robert
Valuable Member
Pretty much any level of nitrate is ok except 0....it's not the key nutrient in the system. Neither is phosphate.
As we discussed earlier - a coral is not a single organism - but actually three. The host, the zooxanthellae and a bacterial component - whose contributing to the host is rather undefined.
The host is an animal - and its wates include ammonia. This is retained and supplies the N to the Zoox who produce carbons - food - for the host. During the light period the zoox can consume all the N produced by the coral and a little more which is drawn from the water column in the form of ammonia or nitrate. Not all corals can uptake nitrate - and most seem to prefrentially take up ammonia first - then nitrate. Corals seem to be able to retain their ammonia during a normal duration dark cycle - so little of the ammonia produced by the host is returned to the water column. If the dark cycle is extened - say to 18 hours or so - most corals will actually contribute N to the water column.
Assuming you have any excess of Nitrate - your fine. Where N comes into play is in balancing P. Too little N couple with too much P - less than a 5:1 ratio - favors organisms which can get their N by fixing Nitrogen gas.
Organism which do this include some of the cyano bacteria and there is some suggestion that bacteria which are resident in corals can do this as well.
So my answer would be - any level of Nitrate is fine as long as its not 0 with respect to corals. The same pretty much applies to phosphate.
The actual issue in our systems is nutrient control with respect to nuisance algaes and bacteria. You can try to contol these by manipulation of N and P but this is a very difficult approach. It is actually easier to control these by limiting C and Fe. C limitation to control bacteria and Fe limitation to control the large cell algaes.
@Thales wrote an article - the link for which appears a couple of posts above - in which he describes the shipwrecks on the Line Island atols. What make these reefs unique - and educational - is that these are high nutriet reefs - much like our tanks tend to be. These reefs, although high nutrient are Fe limited as there is no run-off from terrestrial sources to provide iron and they normally are quite conducive to coral growth - untill a large source of iron - such as a shipwreck occures. Once the Fe liimitation is lifted - algae, cyano and bacterial overgrowth kills the corals for kilometers around - the black reef.
So while its commonly accepted practice in the hobby to concentrate on N and P - we really should be looking at limiting Fe and C.
What do others think?
As we discussed earlier - a coral is not a single organism - but actually three. The host, the zooxanthellae and a bacterial component - whose contributing to the host is rather undefined.
The host is an animal - and its wates include ammonia. This is retained and supplies the N to the Zoox who produce carbons - food - for the host. During the light period the zoox can consume all the N produced by the coral and a little more which is drawn from the water column in the form of ammonia or nitrate. Not all corals can uptake nitrate - and most seem to prefrentially take up ammonia first - then nitrate. Corals seem to be able to retain their ammonia during a normal duration dark cycle - so little of the ammonia produced by the host is returned to the water column. If the dark cycle is extened - say to 18 hours or so - most corals will actually contribute N to the water column.
Assuming you have any excess of Nitrate - your fine. Where N comes into play is in balancing P. Too little N couple with too much P - less than a 5:1 ratio - favors organisms which can get their N by fixing Nitrogen gas.
Organism which do this include some of the cyano bacteria and there is some suggestion that bacteria which are resident in corals can do this as well.
So my answer would be - any level of Nitrate is fine as long as its not 0 with respect to corals. The same pretty much applies to phosphate.
The actual issue in our systems is nutrient control with respect to nuisance algaes and bacteria. You can try to contol these by manipulation of N and P but this is a very difficult approach. It is actually easier to control these by limiting C and Fe. C limitation to control bacteria and Fe limitation to control the large cell algaes.
@Thales wrote an article - the link for which appears a couple of posts above - in which he describes the shipwrecks on the Line Island atols. What make these reefs unique - and educational - is that these are high nutriet reefs - much like our tanks tend to be. These reefs, although high nutrient are Fe limited as there is no run-off from terrestrial sources to provide iron and they normally are quite conducive to coral growth - untill a large source of iron - such as a shipwreck occures. Once the Fe liimitation is lifted - algae, cyano and bacterial overgrowth kills the corals for kilometers around - the black reef.
So while its commonly accepted practice in the hobby to concentrate on N and P - we really should be looking at limiting Fe and C.
What do others think?
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robert
Valuable Member
Something I forgot to point out - old cars,busses and ships are often used to create artificial reefs in nutrient starved waters more typical of tropical reefs (low N and P). In these cases where there is some other limiting nutrient - the algae overgrowth is not an issue and the "black reef" is not produced.
If your tank is high nutrient, then limiting iron is important. If you run an ultra low nutrient system - not so much of a need to limit iron.
One other point - the algaes and cyano produced by excess iron didn't kill the corals directly. They produced carbons which in turn fed bacteria, which then killed the coral. This was demonstrated by the abilty of antibiotics to prevent or limit coral death in the presence of high iron in nutrient rich water.
Together, this is supportive of what I've written in prior posts - limiting simple carbon sources (such as those produced by algaes , POC and DOC) is essential to maintaining bacterial regulation.
If your tank is high nutrient, then limiting iron is important. If you run an ultra low nutrient system - not so much of a need to limit iron.
One other point - the algaes and cyano produced by excess iron didn't kill the corals directly. They produced carbons which in turn fed bacteria, which then killed the coral. This was demonstrated by the abilty of antibiotics to prevent or limit coral death in the presence of high iron in nutrient rich water.
Together, this is supportive of what I've written in prior posts - limiting simple carbon sources (such as those produced by algaes , POC and DOC) is essential to maintaining bacterial regulation.
Its funny, I just changed my frag tank set up last week and I've noticed all of the sudden my acros/montis looking better and growing faster. I was previously running a refugium as part of my old frag tank. So now that its gone, I'm instantly seeing improvements. I can't say for sure this is the cause, but I'm not complaining. My corals are looking better than ever and actually growing faster...
Oceansize
Active Member
My phosphates were at 0.26 when I started dosing GFO for the first time. I had good coral color, but the growth had slowed as the phosphate had risen.
As the phosphate took several days to come down to 0.03 or so, I noticed some very interesting things. Bottom line: my mix of corals, regardless of SPS or LPS, all showed obvious signs of new growth less than 24 hours after my phosphates got below 0.20. They continued to flourish until my phosphates got down to around 0.07, at which point they started to look just a little bit less happy. By the time my phosphates got to 0.03, my acro polyps were no longer extending, colors began to fade, and a majority of my zoa polyps disappeared. That's right: disappeared. Which is different than polyps simply closing up and not opening.
Algae briefly increased upon the addition of GFO (Randy surmises that my system was iron-limited prior to the introduction of GFO, thus the GFO actually fed the algae a lil bit at first) but it quickly melted away, however it was replaced by a new algae that I've never seen before: one that looked an awful lot like iron that's been in water (rusty brownish red, pretty sure it's not cyano). Fortunately that too only appeared for a day or two before beginning to recede.
All of this while nitrates are at an even & steady 2 or 3 ppm.
The point being, my recent experience definitely supports the theory that we want at least some N and P for healthy growing coral. If that feeds more algae than we want, well I just learned firsthand the role that iron plays in algae growth, and so that would support Robert's assertions. It's not the only explanation however, since there is evidence that my system was adequately iron-limited prior to the addition of GFO and yet I still had a lil bit of an algae issue.
My next experiment is to concentrate more heavily on carbon-limiting my system and see how that limits algae growth, but I'm currently waiting for some new stuff to arrive before starting that project, such as finer filter bags for the finer Rox GAC that I am going to use from now on.
As the phosphate took several days to come down to 0.03 or so, I noticed some very interesting things. Bottom line: my mix of corals, regardless of SPS or LPS, all showed obvious signs of new growth less than 24 hours after my phosphates got below 0.20. They continued to flourish until my phosphates got down to around 0.07, at which point they started to look just a little bit less happy. By the time my phosphates got to 0.03, my acro polyps were no longer extending, colors began to fade, and a majority of my zoa polyps disappeared. That's right: disappeared. Which is different than polyps simply closing up and not opening.
Algae briefly increased upon the addition of GFO (Randy surmises that my system was iron-limited prior to the introduction of GFO, thus the GFO actually fed the algae a lil bit at first) but it quickly melted away, however it was replaced by a new algae that I've never seen before: one that looked an awful lot like iron that's been in water (rusty brownish red, pretty sure it's not cyano). Fortunately that too only appeared for a day or two before beginning to recede.
All of this while nitrates are at an even & steady 2 or 3 ppm.
The point being, my recent experience definitely supports the theory that we want at least some N and P for healthy growing coral. If that feeds more algae than we want, well I just learned firsthand the role that iron plays in algae growth, and so that would support Robert's assertions. It's not the only explanation however, since there is evidence that my system was adequately iron-limited prior to the addition of GFO and yet I still had a lil bit of an algae issue.
My next experiment is to concentrate more heavily on carbon-limiting my system and see how that limits algae growth, but I'm currently waiting for some new stuff to arrive before starting that project, such as finer filter bags for the finer Rox GAC that I am going to use from now on.
robert
Valuable Member
If you watch the video - you may be back at thinking that elimination of N and P is the way to go...Just remember high N and P didn't directly impacct the corals - they simply lead to elevated C which in turns feeds the bacteria and this kills the corals.
Growing algae or carbon dosing to lower N and P potentially exacerbates issues - particularly during a die off or sustained use. I'm not a fan of either of these methods as they address the problem by first assuming the wrong nutrients are in play.
There are High Nutrient Low Carbon (HNLC) reefs - these exist because thay are situated in open ocean, well away from land sources of iron.
Very very little iron is found in your water - but you add it with every feeding and it concentrates in organic complexes in your tank - deutritus - much in the same manner as phosphate. Algae holds reserves of iron - so again macros work against you.
Limit carbon, (DOCand POC) - to maintain control over your bacterial load. It doesn't matter what you N and P are - limit iron and you can't grow algae. No algae means low sugars, which means bacteria stays in regulation.
Your corals will get the iron they need from the food they capture.
Virtually any level of N and P seems ok. I've been doing this for a year now.
Growing algae or carbon dosing to lower N and P potentially exacerbates issues - particularly during a die off or sustained use. I'm not a fan of either of these methods as they address the problem by first assuming the wrong nutrients are in play.
There are High Nutrient Low Carbon (HNLC) reefs - these exist because thay are situated in open ocean, well away from land sources of iron.
Very very little iron is found in your water - but you add it with every feeding and it concentrates in organic complexes in your tank - deutritus - much in the same manner as phosphate. Algae holds reserves of iron - so again macros work against you.
Limit carbon, (DOCand POC) - to maintain control over your bacterial load. It doesn't matter what you N and P are - limit iron and you can't grow algae. No algae means low sugars, which means bacteria stays in regulation.
Your corals will get the iron they need from the food they capture.
Virtually any level of N and P seems ok. I've been doing this for a year now.
Turbonut
Community Member
Absolutely interesting. I need to test iron in my tank. You might have just answer my question. My p04 is at .57 due to dry rock leaching although with p04 this high and my mh's running 6hrs a day no algae film or any algae for that matter exist in my tank, there is some coralline growing on the rocks but that's it. I really need to look into this more.
blackgate
Active Member
Well like I said earlier, I have been tinkering with the idea of getting rid of my macros for a while now. Do you think it best just to run ROX carbon and some gfo and leave it be?
Oceansize
Active Member
I can't speak for Robert, but I've had good success not worrying about PO4 (no fuge, no macro, no GFO), but always running Rox GAC (along with other carbon-limiting such as grazers, mechanical filtration and UV). Once my phosphate got above 0.25 (took almost a year), I did start getting algae, so I added some GFO at the recommended dosage. Although it did lower my PO4, my algae actually got worse, but it was a different strain that what had been building up previously. This new algae was decidedly more rust colored instead of green. The most logical conclusion is that my system was relatively iron-limited previously (due to GAC?) but the addition of GFO released enough iron that my system was no longer iron-limited and this allowed algae to flourish despite PO4 dropping.
According to Randy, PO4 needs to be below 0.03 if you don't want it to contribute to algae growth, but I find this is too low for my coral. I stopped getting polyp extension from my one acro once PO4 dropped below 0.18, but I still got algae growth.
Now that my PO4 is 0.03, I've taken the GFO out. I want to see what level my PO4 needs to get back up to for my acro polyps to come back out. If/when I put the GFO back in, I will be doing so with only 1/4 to 1/8 of the recommended dosage. Iron-limitation seems to be a great algae-killer that I sort of lucked into and Robert and Randy have possibly explained, so GFO must be used extra-sparingly if iron-limitation is the goal.
The point being, I feel I have avoided many nutrient-related issues that others frequently encounter and the one consistent difference seems to be that I've been running GAC and UV 24/7 ever since my tank cycled a year ago. During that time I also did nothing specific to address PO4 accumulation and it only became something I needed to deal with after almost a year with minimal water changes. I'm not claiming to be smart, just lucky. I got into the habit of running GAC and UV 24/7 from my freshwater days. The other point being, GFO works better as a preventative rather than a reducer because the dose needed to reduce PO4 contributes too much iron, apparently. Once I get PE back on my acro I will be trying to maintain PO4 at whatever level it is at that point, using tiny tiny amounts of GFO and see if I get any algae again after adding back that tiny amount of GFO.
Edit: I misspoke, I have NOT been running UV since Day 1. I discovered a few months later that the bulb was actually burnt out. And when I replaced it, I experienced one of the quickest, most profound reductions in algae I've ever seen in my 13 years of keeping aquaria. How could I forget this when it was the one event that made me a fan of UV for life?!? So yeah, to answer your question: just run some Rox GAC, a teeny amount of GFO, !add a UV!, and then leave it be. LOL
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KingTriton
Active Member
Ive tried dosing potassium nitrate as my system maintains a NO3 of O. That said whenever I dose the nitrate above 0.2-0.5ppm my algae wants to come out, which makes it to where I have to stop dosing. I swear I have Dino which only shows up when the NO3 are above .2-.5. Anyone have any advice on this one as I would like to have nitrates without the algae issue.
Oceansize
Active Member
Have you/Are you running GAC or UV? I have been avoiding algae with nitrates as high as 2.0 - 5.0 ppm and phosphates as high as 0.20 ppm, but I'm always running GAC and UV. Robert makes a strong case for why these carbon- & iron-limiting strategies are working for me even though I'm above traditional ULNS parameters.
How are you achieving denitrification?
Redbarnreefer
Active Member
@Battlecorals
Adam, for export do you water change or are your corals eating all your nutrients? I'm guessing you run a skimmer, what else?
Adam, for export do you water change or are your corals eating all your nutrients? I'm guessing you run a skimmer, what else?
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