Just to clarify a couple points:
For starters chaeto produces far less DOC than what we call nuisance algae. Keeping it in a system does not carry the risk having a lot of nuisance algae has. I would much rather do a cryptic sump/refugium than a lighted sump/refugium though.
There are huge differences in the DOC (this includes sugars) released by algae and the DOC released by corals. Looking at Haas, et al, the DOC released by algae is promoting heterotrophic microbial activity that includes pathogeinc to corals, DOC released by corals promotes autotrophic microbial processes. Klunts & Kline have research showing DOC released by algae have a far worse effect on corals than inorganic nitrogen and inorganic PO4
Links for Haas, et all
https://www.sciencedaily.com/releases/2016/04/160425141821.htm
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3719129/
http://www.nature.com/ismej/journal...161a.html?message=remove&foxtrotcallback=true
Links for Klunts & Kline:
http://scrippsscholars.ucsd.edu/dkl...carbon-and-nutrient-stressors-three-caribbean
http://www.int-res.com/articles/meps2006/314/m314p119.pdf
Feldman, et al, (links are in post #18 my skimmerless thread) looked at skimmers and it's anybodies guess how much a skimmer is pulling out an any given time. Best case scenario is about 30% but often a skimmer might only be pulling out 10% or 15%. More importantly in my view is skimmers are really skewing the microbial population and we have no clue if it's beneficial or harmful long term. In light of the overwhelming evidence from all the life sciences on the importance of a healthy microbial balance it doesn't make sense to me to use one.
Scrubber_steve
I'm really very likeable
Hi Timfish. Thinking about the selective removal of bacteria from the water column by skimming, & the pathogens supplemented to varying degrees by algae, what is your opinion on the use of UV sterilizers?
Thanks Timfish for all the papers posted .it takes a while to go thru them. It's the problem of nuisance algae popping up that I have. I have two foxface in a two month prophylaxis and QT tank starting today and also some turbo snails . I have purchased zeolite and currently have some Seachem Matrix which is supposed to allow for bacterial anaerobic conversion of nitrate. Too little footprint under this 45 for all of these zones in addition to felt socks , skimmer, and return pump. I purchased better T5 bulbs today and will try to rearrange under sump to fit light fixture back in for the Chaetomorpha . Will try to put some substrate for the sponges in a low flow chamber. Cramming this all in a 20gal tall sump. Hard to do. I like the skimmer and the GAC to keep the water from yellowing so much. I guess I am trying to adsorb excess nutrients but also allow for natural recycling and binding of nutrients thru different zones. I will see how this works.
Scrubber_steve
I'm really very likeable
sorry to but in, but I'd imagine the small amounts of algae used in fuges & scrubbers (not forgetting its regular removal after growth) and any subsequent release of pathogens would easily be controlled by activated carbon.
I'd be curious if these pathogens are released from the algaes while simply growing, or the die back, or indirectly by fish after eating the algae?
Scrubber_steve
I'm really very likeable
In Feldmans article - Bacterial Counts in Reef Aquarium Water: Baseline Values and Modulation by Carbon Dosing, Protein Skimming, and Granular Activated Carbon Filtration http://www.advancedaquarist.com/2011/3/aafeature he showed that the study's aquariums using no skimmers or GAC had higher TOC content than natural reef waters (NRW) but water column bacterial counts equal to NRW.
The study's aquariums that used skimmers and GAC had TOC levels equal to NRW but water column bacteria counts far lower than NRW.
Feldman noted that SPS corals do well in the skimmed, GAC aquariums but not in the aquariums with TOC levels slightly higher than, and water column bacteria counts equal to NRW.
I'd take two things from this. one, sps don't particulaly like water column bacteria content above a certain level, no matter the cause (carbon dosing or algae) or type of bacteria. And two, perhaps a useful purpose of a skimmer is the removal of water column bacteria.
Curiously and counter intuitive, the one tank Feldman looked at in his paper on bacterial counts found a sterilizer didn't affect the bacterial counts like a skimmer does. For the record I only use a sterilizer to deal with ick and velvet and do not see any good reason to run one continuously on a reef system and will not run one unless I have a parasite issue, which is uncommon since I QT everything before adding them to any of my tanks. But with only ONE example and the flow rate and wattage was not given we still do not have any long term research on a sterilizers influence on the microbial populations in reef systems.
You're welcome!
Delbeek and Sprung in "The Reef Aquarium" VOL III discuss the decision by scientists at the ReefHQ Mesocosm on the Great Barrier Reef Marine Park Authority in Australia to remove their algae scrubber after 16 years to deal with water quality issues. Dr. Adey's research that led to his development of algae scrubbers was a huge step forward in our understanding how reefs work but research since then, particularly the role of DOC and it's influence on microbial processes, has raised serious questions about the long term use of both algae scrubbers and carbon dosing. A significant point that has profound ramifications for carbon dosing, de Goeij's research shows cryptic sponges remove DOC in minutes that takes bacteria weeks to remove. As we learn more about the roles of cryptic sponges in our reef systems in recycling DOC and removing bacterioplankton much of the successes attributed to those two methodologies are probably in reality due to cryptic sponges removing either or both the DOC released by algae or added with carbon dosing as well as removing the bacteria DOC promotes. (And sugar is DOC)And regarding your question about various amount of DOC released by algae Dr. Haas gave a presentation on it to the local reef club 2 years ago on his research that showed DOC was completly removed in eutrophic system completely dominated by what we call nuisance algae. He had a chart showing the amount of DOC released by by different types and chaeto and halimeda were at the bottom. I've not bought some of his papers which might contain the info but I do have an emial to him and will pass on specifics when I get them.
Scrubber_steve
I'm really very likeable
You're welcome!
Hi Timfish. Not wanting to sound rude, but what you've stated above could not be further from the truth in regards to why the Algae Turf Farm (ATF) was removed at the Great Barrier Reef Marine Park Authority (now Reef HQ & Coral Reef Exhibit) particularly in regards to dealing with water quality issues. Lets look at the facts concerning the algae scrubbers & the measures taken to improve water quality to improve coral mortality rates.
The algae scrubbers were in operation from 1987 to 2002 and were removed from the Coral Reef Exhibit (CRE) at the GBR Aquarium because -
1. Most importantly, the Algae Turf Farms effects on CRE filtration were negligible, especially when compared to the CRE's overall internal algal mass productivity. The ATF only accounted for 0.1% of systems overall algal mass)
2. they were too labour intensive (algae removal & servicing of troublesome dump buckets). The ATF consisted of 70 shallow PVC trays approximately 2 m in length and 1 m in width.
3. The pvc used to build the scrubbers was leaching toxins into the water. Possibly because they were affected by direct sun light. I know this because I was given a personal behind the scenes tour of the Aquarium in March this year by the Aquarium's Curator.
Now lets look at the actual measures taken to improve water quality to improve coral mortality rates.
A significant shift occurred during 2002 with how the CRE was maintained when the aquarium was closed to the public for almost five months to maintain and upgrade the facility.
The CRE history is divided into two periods "“
The "œOceanic Water period" (pre-2002) Average corals survival rate was only 20% to 30%
The "œEstuarine Water period" (2002 to present) corals survival rate increased to 70% to 80% (possibly higher now).
The changes made to the systems maintenance that were considered most critical to improving coral survival were "“
1. The switch from using priori ultra-clean oceanic water, collected offshore by barge, to using "˜less pure' estuarine water collected on the incoming tide from the Ross Creek to increase nutrients and provide an external source of plankton.
2. The removal of internal mechanical filtration (three large sand filters). This improve overall tank health by avoiding "˜over stripping' the water column of particulates and encouraging plankton production, greater food availability, and larval settlement, especially during spawning periods
3. Internal circulation was increased.
4. The use of calcium chloride to raise average calcium levels (~ 250 mg Ca2+.L-1, to 420 mg Ca2+.L-1)
https://www.burgerszoo.com/media/560570/chapter-26.pdf
https://www.burgerszoo.com/media/560502/chapter-9.pdf
dz6t
New member
Cryptic Sponge & Sea Squirt Filtration Methodology
Cryptic Sponge & Sea Squirt Filtration Methodology
I found this article by Haas.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0027973
Quote:
turf algae produced nearly twice as much DOC per unit surface area than the other benthic producers (14.0±2.8 µmol h−1 dm−2), stimulating rapid bacterioplankton growth (0.044±0.002 log10 cells h−1) and concomitant oxygen drawdown (0.16±0.05 µmol L−1 h−1 dm−2).
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Cryptic Sponge & Sea Squirt Filtration Methodology
I found this article by Haas.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0027973
Quote:
turf algae produced nearly twice as much DOC per unit surface area than the other benthic producers (14.0±2.8 µmol h−1 dm−2), stimulating rapid bacterioplankton growth (0.044±0.002 log10 cells h−1) and concomitant oxygen drawdown (0.16±0.05 µmol L−1 h−1 dm−2).
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karimwassef
Active member
I don't see an issue with higher DOC. It's more food flowing in the system.
Scrubber_steve
I'm really very likeable
Good points! I'm going to have to go back and reread Feldman's research.
When you do, take note of Table 1. "Bacterial counts from authentic marine water, various control samples, and several reef tanks".
Look at the specs for Sanjay's first 3 listed tanks - his 55, 29 and 28g tanks.
None of these use a skimmer, yet one, the 28g has significantly lower water column bacteria counts than the other two.
The only difference between these three of Sanjay's tanks is, his 28g has a sandbed.
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dz6t
New member
Cryptic Sponge & Sea Squirt Filtration Methodology
Cryptic Sponge & Sea Squirt Filtration Methodology
I suspect there was a large amount of bacteria in the 28g with sand bed were on the sand bed. Assuming there are similar TOC per gallon in those three tanks.
I guess different inhabitants in those tanks as well as different feeding regiments can cause the difference as well.
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Cryptic Sponge & Sea Squirt Filtration Methodology
I suspect there was a large amount of bacteria in the 28g with sand bed were on the sand bed. Assuming there are similar TOC per gallon in those three tanks.
I guess different inhabitants in those tanks as well as different feeding regiments can cause the difference as well.
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karimwassef
Active member
I keep a 3" sand bed and the fauna there is amazing... detritus consumers from cucumbers to worms... that's step 1 in my poop loop.
No worries!
To better understand what's been happening in my tanks for the last 3 decades I've needed to constantly go back and reread and review what I know when I come across new information.
