Hello,
I'm including in this post the original emails that I exchange with WetWebMedia several month ago. I'm interested to hear your opinion on what is going on with my sand bed and the ways I'm thinking of salvaging it.
Since the time I wrote the original post to WetWebMedia things got a bit worse. The Cyano has disappeared only to be replaced with caulerpa racemosa taking over the tank. I have upgraded the skimmer to AquaC EV-180 and added two Tunze Stream Pumps to increase the circulation within the tank. The skimmer is now producing a cup of dark stuff a day and I keep cleaning the collection cup twice a week.
I have also started replacing 6gal of water twice a week. I still use carbon and began to use RawPhos to see if I can eliminate any traces of phosphate that might be in the water but not detected by my test kit. I have been also trying to prune the caulerpa as much as possible. It actually slowed down or almost stopped its growth, and it even looks that some patches are actually getting white or clear. Unfortunately this seems to be fouling up the water in the tank and all the corals are looking REALLY bad and some seems to be dieing.
I have tried to remove as much of it as possible but it is hard. When pulling it from the sand, it tends to stir it up quite a bit and it is almost impossible to get it off the rock.
I have been thinking about pulling the rock out, scraping the algae off (somehow) and then putting it all back. I'm guessing that it would be best to do it with as much of the life stock out as possible and to re-introduce the critters back as soon as the "dust" settles.
Additionally I was thinking about carefully adding a bit of sand (~1") since the deep sand bed has gotten not so deep (I'm guessing that the aragonite tends to dissolve over time) and is now between 5-4" (possibly less deep in a few spots) deep instead of 6-5" as it was when I first put it in.
Is it common for the deep sand bed to have purple/green discoloration in places where the sand is pilled up against the glass starting at the dept of about 1" and greater?
Is it also common when a thin layer of the sand gets disturbed to see somewhat grayish color below?
Does the above approach make sense? Is there anything that I should do differently, not do at all, or is there something that I'm missing?
I'm hoping that this coupled with several larger water changes and the skimmer working at its peek efficiency should be the end of my troubles.
Thank you,
Petr
------ OLD POST --------
Cyanobacteria and DSB
Hi, I have a question about cyanobacteria in my tank (120gal, ~5" Southdown play sand DSB, ~70lbs or rock, close loop circulation Anthony's design powered by Dolphin AquaSea pump ~2,100 gal/hour, built-in glass overflow Anthony's design with a sump and Iwaki 20RLT pump, 2x 250W MH Ushio 10,000K + 2x 65W Actinic PC, Turbofloor 1000 skimmer, home made CO2 calcium reactor using Knop Korallith). Currently I have what I believe a very low bio-load in the tank (one juvenile Six Line Wrasse, one juvenile Banggai Cardinal, Cleaner Shrimp, Cerith snails (a lot), a few blue legged hermit crabs, ~10 SPS frags and some softies). I should also mention that I use RO/DI water (membrane, sediment filters and GAC replaced around X-mass) for water changes 5gal/week (it sits for a few days in a bucket with a powerhead and then I add the salt and after it sits for another day or so then I use it for water changes)
<All good thus far...>
and that I do check the specific gravity, temperature and pH before I use it. I run activated carbon 24x7 and I've been always using Black Diamond. In the recent month it was somewhat difficult to obtain and so I've used other brands as well (Pro-Carb & Kent Reef Carbon). I have been changing about a half of the carbon every other week and cleaning the sump about once a month.
Over past two month I've been observing small patches of cyano spreading over the sand bed.
<Happens>
My lights (bulbs are less than 6 month old) go on at 12:30pm and go off at 11:30pm in the evening. Early in the morning I can't almost see any cyano but as the day goes on it is more and more visible.
<Well stated>
When the lights are turned on the cyano starts slowly disappearing with the exception of the places that are brightly illuminated. By the time the lights go off a lot of it disappears. I've started being VERY careful about how much I feed the fish (once a day with a turkey baster trying to feed as fast as they can catch the food to minimize any food being uneaten). I'm feeding a home made frozen food containing some Nori, scallops, shrimp, krill, brine shrimp and Selcon.
Since the cyano appeared I started executing water changes more frequently (about 5 gallons 3 times per week) and cleaning the skimmer collection cup 2 times a week. While checking all the equipment trying to identify the culprit I noticed that the hose that feeds the skimmer with the raw water was partially blocked by the calcium deposits that accumulated on its walls and subsequently got loose. I guess this can explain why the water quality deteriorated and DOC concentration increased.
<... would think it would decrease>
I have noticed that about a month ago, cleaned up the skimmer and the hoses immediately and have been checking it once a week since. I had also some issues with the calcium reactor and the pump re-circulating the water within the reactor. This lead so drop in the alkalinity and Ca levels, which I have tried to correct for a short period of time with dosing both Seachem's Reef Advantage Calcium (calcium oxide) and Kalk shots (as advocated by Anthony in his book). Once I got the necessary equipment, I fixed the Ca reactor and phased out any other dosing. Now the alkalinity is around 3.77 meq/L (Salifert), Ca 360ppm (Seachem), Total NO3 Nitrate ion concentration is below 12.5mg/L (Tetra), Phosphate is not detectable (Seachem) and the pH is between 8.1 (morning) and 8.2 (evening) (Seachem).
<Again, all sounds good>
I tried to vacuum some of the cyano from the surface of the sand bed with as little of the sand as possible and noticed that about ? inch thick top layer of the sand is bound (not fused) together. It can be broken up easily with the hose I used to vacuum the cyano or with the scraper.
I acknowledge that my water quality has not always been perfect (I used to have a yellow tang and used to feed more heavily) but I think that it has improved a lot in the last two month. However, it seems that my effort is not stopping the slow progress of the cyano. I have been reading various articles on the net about DSB lately and notice a few that talk about so called "crash" of DSBs and how cyano problem is indicative of such crash. Is my DSB crashing?
<Doubtful, no>
Can I recover from this problem or is the DSB doomed to be completely replaced?
I will be looking forward to your reply.
Regards,
Petr
<Mmm, well, you really don't have a "problem" as far as I can see, evaluate from the above... transient Cyano/BGA is common... to nearly unavoidable, given the make-up, maintenance you list... There are a few things you can do to speed up the "centering" of the system (that will occur in time...). You might convert part or all of the sump to a lighted refugium, with purposeful macroalgae... You could upgrade your skimmer... You might add an ozonizer... Or "just relax" and not sweat this small, likely transient occurance. Bob Fenner>
I'm including in this post the original emails that I exchange with WetWebMedia several month ago. I'm interested to hear your opinion on what is going on with my sand bed and the ways I'm thinking of salvaging it.
Since the time I wrote the original post to WetWebMedia things got a bit worse. The Cyano has disappeared only to be replaced with caulerpa racemosa taking over the tank. I have upgraded the skimmer to AquaC EV-180 and added two Tunze Stream Pumps to increase the circulation within the tank. The skimmer is now producing a cup of dark stuff a day and I keep cleaning the collection cup twice a week.
I have also started replacing 6gal of water twice a week. I still use carbon and began to use RawPhos to see if I can eliminate any traces of phosphate that might be in the water but not detected by my test kit. I have been also trying to prune the caulerpa as much as possible. It actually slowed down or almost stopped its growth, and it even looks that some patches are actually getting white or clear. Unfortunately this seems to be fouling up the water in the tank and all the corals are looking REALLY bad and some seems to be dieing.
I have tried to remove as much of it as possible but it is hard. When pulling it from the sand, it tends to stir it up quite a bit and it is almost impossible to get it off the rock.
I have been thinking about pulling the rock out, scraping the algae off (somehow) and then putting it all back. I'm guessing that it would be best to do it with as much of the life stock out as possible and to re-introduce the critters back as soon as the "dust" settles.
Additionally I was thinking about carefully adding a bit of sand (~1") since the deep sand bed has gotten not so deep (I'm guessing that the aragonite tends to dissolve over time) and is now between 5-4" (possibly less deep in a few spots) deep instead of 6-5" as it was when I first put it in.
Is it common for the deep sand bed to have purple/green discoloration in places where the sand is pilled up against the glass starting at the dept of about 1" and greater?
Is it also common when a thin layer of the sand gets disturbed to see somewhat grayish color below?
Does the above approach make sense? Is there anything that I should do differently, not do at all, or is there something that I'm missing?
I'm hoping that this coupled with several larger water changes and the skimmer working at its peek efficiency should be the end of my troubles.
Thank you,
Petr
------ OLD POST --------
Cyanobacteria and DSB
Hi, I have a question about cyanobacteria in my tank (120gal, ~5" Southdown play sand DSB, ~70lbs or rock, close loop circulation Anthony's design powered by Dolphin AquaSea pump ~2,100 gal/hour, built-in glass overflow Anthony's design with a sump and Iwaki 20RLT pump, 2x 250W MH Ushio 10,000K + 2x 65W Actinic PC, Turbofloor 1000 skimmer, home made CO2 calcium reactor using Knop Korallith). Currently I have what I believe a very low bio-load in the tank (one juvenile Six Line Wrasse, one juvenile Banggai Cardinal, Cleaner Shrimp, Cerith snails (a lot), a few blue legged hermit crabs, ~10 SPS frags and some softies). I should also mention that I use RO/DI water (membrane, sediment filters and GAC replaced around X-mass) for water changes 5gal/week (it sits for a few days in a bucket with a powerhead and then I add the salt and after it sits for another day or so then I use it for water changes)
<All good thus far...>
and that I do check the specific gravity, temperature and pH before I use it. I run activated carbon 24x7 and I've been always using Black Diamond. In the recent month it was somewhat difficult to obtain and so I've used other brands as well (Pro-Carb & Kent Reef Carbon). I have been changing about a half of the carbon every other week and cleaning the sump about once a month.
Over past two month I've been observing small patches of cyano spreading over the sand bed.
<Happens>
My lights (bulbs are less than 6 month old) go on at 12:30pm and go off at 11:30pm in the evening. Early in the morning I can't almost see any cyano but as the day goes on it is more and more visible.
<Well stated>
When the lights are turned on the cyano starts slowly disappearing with the exception of the places that are brightly illuminated. By the time the lights go off a lot of it disappears. I've started being VERY careful about how much I feed the fish (once a day with a turkey baster trying to feed as fast as they can catch the food to minimize any food being uneaten). I'm feeding a home made frozen food containing some Nori, scallops, shrimp, krill, brine shrimp and Selcon.
Since the cyano appeared I started executing water changes more frequently (about 5 gallons 3 times per week) and cleaning the skimmer collection cup 2 times a week. While checking all the equipment trying to identify the culprit I noticed that the hose that feeds the skimmer with the raw water was partially blocked by the calcium deposits that accumulated on its walls and subsequently got loose. I guess this can explain why the water quality deteriorated and DOC concentration increased.
<... would think it would decrease>
I have noticed that about a month ago, cleaned up the skimmer and the hoses immediately and have been checking it once a week since. I had also some issues with the calcium reactor and the pump re-circulating the water within the reactor. This lead so drop in the alkalinity and Ca levels, which I have tried to correct for a short period of time with dosing both Seachem's Reef Advantage Calcium (calcium oxide) and Kalk shots (as advocated by Anthony in his book). Once I got the necessary equipment, I fixed the Ca reactor and phased out any other dosing. Now the alkalinity is around 3.77 meq/L (Salifert), Ca 360ppm (Seachem), Total NO3 Nitrate ion concentration is below 12.5mg/L (Tetra), Phosphate is not detectable (Seachem) and the pH is between 8.1 (morning) and 8.2 (evening) (Seachem).
<Again, all sounds good>
I tried to vacuum some of the cyano from the surface of the sand bed with as little of the sand as possible and noticed that about ? inch thick top layer of the sand is bound (not fused) together. It can be broken up easily with the hose I used to vacuum the cyano or with the scraper.
I acknowledge that my water quality has not always been perfect (I used to have a yellow tang and used to feed more heavily) but I think that it has improved a lot in the last two month. However, it seems that my effort is not stopping the slow progress of the cyano. I have been reading various articles on the net about DSB lately and notice a few that talk about so called "crash" of DSBs and how cyano problem is indicative of such crash. Is my DSB crashing?
<Doubtful, no>
Can I recover from this problem or is the DSB doomed to be completely replaced?
I will be looking forward to your reply.
Regards,
Petr
<Mmm, well, you really don't have a "problem" as far as I can see, evaluate from the above... transient Cyano/BGA is common... to nearly unavoidable, given the make-up, maintenance you list... There are a few things you can do to speed up the "centering" of the system (that will occur in time...). You might convert part or all of the sump to a lighted refugium, with purposeful macroalgae... You could upgrade your skimmer... You might add an ozonizer... Or "just relax" and not sweat this small, likely transient occurance. Bob Fenner>
