Where to begin? In my last update I mentioned the sand had started to look a bit green and generally manky looking (scientific term, lol). At the start of August I noticed a patch of sand at the back of the tank had developed a suspicious brown look to it. It didn't look quite like diatoms and warning bells were ringing so I dusted off the microscope for a closer look.
This is how the sand looked at the back...
...and this is what I saw under the microscope:
So yeah it was dinoflagellates but not a species I had encountered before, this was large cell Amphidinium. Apparently this species is not toxic to livestock but can be much harder to get rid of. The best way to tackle it is to outcompete it by encouraging the growth of diatoms, to do that you have to raise the silicate level so I ordered myself a bottle of Brightwell's SpongExcel. I have since found that this is not the cheapest approach as it's not very concentrated, Waterglass is much most cost effective but at least it would get me started. Apart from the dinos making the tank look dirty nothing seemed to be suffering or dying so I took my time with the dosing, starting off slowly. It's pretty hard to test silica levels with home kits, Hanna do make one but it's aimed at freshwater and doesn't work well for saltwater so I didn't see the point of buying it.
In addition to silica dosing I decided to get a better grip on the nutrient levels. At the beginning of August the nitrate level was around 2.5ppm thanks to dosing NeoNitro but phosphate was still extremely low often registering as 0 on the Hanna ULR. I invested in some NeoPhos and started dosing that too (bonkers really!).
A sand sample taken just over two weeks later looked like this...
There were still dinos present but now I was also seeing some diatoms mixed in as well. I continued to dose silica but still at a lower amount than is normally recommended. The phosphate level had risen to approximately 0.04ppm on the Hanna ULR by the end of August. By mid September I realised that the orignal brown patches at the back of the tank had faded away. I sampled the sand on the 11th September I couldn't find any Amphidinium under the microscope, this was honestly quite a surprise to me as I'd expected to see some still hanging around. So my sand was clean right? Well no, I had replaced one sort of brown for another.
This was the 'new' brown...
I stopped dosing silica and by that time the phosphate was up to 0.06ppm or thereabouts so I decided to hold off dosing any more of that too. By October the sand had progressed from brown to green when cyanobacteria decided to join the party too. It's even got the audacity to smile at me under the microscope!
At the time of typing this the sand is a mix of green and brown. I'm not so bothered about the diatoms because the CUC love it but the cyanobacteria is nasty. So how do I combat green Cyano? I did think about using Dr Tim's Re-fresh but it states on the bottle that it could be harmful to snails and shrimps. I queried this with the manufacturer but they wouldn't elaborate as to how serious the risk was or even how the livestock is affected, is it toxic to them or do they die because of a knock on effect? I'd also rather not use chemicals such as Chemiclean either. So I have an imbalance between the nitrate and phosphate levels right? They currently stand at around 4.5 ppm for nitrate (Salifert) and 0.06-0.09ppm phosphate (Hanna ULR, the test results vary from day to day). Should I keep raising the nitrate (I am still dosing NeoNitrate every day) or try and reduce phosphate, or do both? I did add a couple of new fish at the beginning of September in the hope of addressing the nitrate issue but there was no noticeable effect. Maybe I need to add a few more?
The struggle continues...
I let the tank and myself have a breather for a week following 'clamgate'. Clive the clam appears to be fine after the incident and I'm pleased to report that nothing succumbed to an excess of clam ‘protein'. Then I transferred over my two remaining Acropora (gomezi and hyacinthus). I'd been putting off moving these because as we all know SPS can be tricky in new systems but it had to be done and if they didn't make it that'll be that. The A. gomezi was super easy because it's a tiny frag on a frag plug but the A. hyacinthus had grown rather large. I tried my best to frag it off the rock in one complete piece but, yeah that didn't happen. It broke into three, I was going to keep the two largest but in the end I opted to add a single bit only (easier to fix down). Those who followed my old thread may remember that the Reefer 170 had an issue with red bugs. I hadn't seen any of the little red devils for ages but that doesn’t mean that they were all gone, I can only hope. I dipped both frags in Reef Primer and checked them quite thoroughly before they were transferred.
Now we get to the big one. On the 26th April I decided to complete the tank transfer and shut the Reefer down. Prior to this I made one last concerted effort to catch Rei the yellow wrasse and Spike firefish but Rei would only poke his head briefly into the trap and Spike avoided it entirely so it was simply a no go. We did try catching the Spike using nets and acrylic baffles, much chaos ensued with the tiny fish outwitting us every time.
The strip down progressed pretty much as planned with no disasters to speak of, I found it quite stressful nonetheless. We emptied out the water and rocks in stages. The corals that I wanted to keep were cut off and placed in one bucket with the remaining rocks/corals going into another. Spike the firefish was cornered with a net and safely removed. Ming the Pom pom crab was discovered clinging to the underside of a rock. Finally we were left with a tank containing a little water, one last piece of rock and sand. With my breath held, the rock was lifted out revealing Al the pistol shrimp and Flash his Whitecap goby partner hiding underneath. Phew! A careful bit of sand exploration was required to flush out Rei the yellow wrasse. Swipes the porcelain crab was MIA at that point so we had to carefully go back and examine every bit of rock again placing them one by one back into the Reefer as we went. Finally we discovered her hidden in a hole in one of the base rocks. That was pretty much it except for one last thing of note, I discovered a rather scary number of Aiptasia living in the overflow weir along with half a dozen baby sun corals.
Following the transfer Rei the yellow wrasse hid in the sand for a whole 10 days before finally deciding to make an appearance. I honestly thought he’d died from stress or something. Everything else made it through OK which I’m relieved about. The fish were naturally pretty freaked out however so I didn’t take any photos for ages.
The Acros are still alive and growing but have lost colour which is probably down to the poor nutrient situation. There have been a number of reports circulating recently that TMC eco reef rock leaches phosphate and silicates but apart from a brief spike of phosphate during the cycle that hasn’t been my experience at all. Nitrate and phosphate have been consistently registering as zero on my test kits (Salifert and Hanna respectively). In the old days this wouldn’t have bothered me much but the internet has taught me to fear the dreaded D word. For a while I saw a little growth of what looked like some brown algae on the rocks but when viewed along the length of the tank with natural lighting behind was in fact green hair algae. There must have been some nutrients knocking about somewhere to fuel the growth. This algae started to become a little more pronounced so I decided the CUC needed a tiny boost. Two weeks and 6 small Trochus snails later most of this algae was gone, I felt quite pleased with myself. However the removal of the hair algae shifted the balance somehow and combined with a lack of nutrients I began to see the appearance of dinoflagellates on some of my gorgonians. Normally I would take a watch and wait approach but it’s hard not be affected by some of the algae horror stories I have read online. I dusted off the microscope and identified the species as Ostreopsis, fearing a full blown infestation along with the death of my beloved snails I decided action was required in the form of nitrate dosing. I had already been feeding quite heavily to that point including Reef roids and phytoplankton but it didn’t seem to have made any measurable difference. It felt wrong to be actually dosing nitrate! I began with a laughably tiny amount (0.5ml of Brightwell’s NeoNitro per day, 12.6ml will raise my tank volume by 1ppm so 0.5ml was nothing lol). After 6 weeks I gradually increased the dose to 4ml per day, during this time the dino growth increased slightly, mainly evident on the gorgonians, but never turned into the major disaster I feared. The gorgonians still had their polyps extended and the snails seemed fine too. I continued my weekly water change regimen using the opportunity to siphon as much of the dinos as possible every time (not recommended I know but I like to perform water changes).
When the tank was 4 months old I sent off the first ICP sample. I discovered elevated levels of Cobalt and Aluminium. I have no idea where they have come from, leeching from the rock maybe? The nitrate level was 0.02mg/l, phosphate was 0.03mg/l and silicate was 66ug/l. Iodine was a bit low as expected (and some other elements low as per usual).
Finally after 7 weeks of dosing nitrate I started to register 1ppm on the Salifert kit, incredibly the dinos started to recede! This might have been a coincidence of course and nothing at all to do with the nitrate level but either way I am happy.
I am curious to know why I’m not registering a release of phosphate and/or silicate from the TMC eco reef rock. Perhaps the corals are soaking up the nutrients as they are released, the gorgonians are growing very fast. Or maybe the rock is hatching a plan to trip me up later on down the road.
I have lots to update, hmm where to begin? I think I should probably get the bad stuff out of the way first.
Forgive me Father for I have sinned. For quite a while I had noticed that I was harvesting less and less macro algae from the refugium, growth had slowed to almost nothing at all despite there being plenty of nitrate and phosphate available. The days of my tank having low nutrients were certainly in the distant past as they had been slowly but surely creeping up. At the last ICP analysis nitrate was sitting at 11.5mg/l and phosphate at 0.13mg/l. I'd also noted that the mini brittle stars that used to thrive in amongst the algae had dwindled from hundreds to zero (there are still lots in the DT). I'd come to the conclusion that Charlize the hitchhiker crab had been supplementing her diet with some brittle star meat. Anyway hair algae had taken a firm hold in the upper half of the refugium and was choking out the growth of macro algae below. This meant that there was even less algae available to the crustacean residents (Charlize and also Bruce the Emerald crab) at the bottom of the refugium. Then at the beginning of December, I discovered what was left of Bruce, had he also been eaten by Charlize? RIP Bruce.
So on the 16th December 2019 I decided then to take the refugium out for a good clean, removing the old mud substrate and replacing it with some new, a long overdue task I must admit. I carefully salvaged as much of the macro algae as I could (a mix of Caulerpa racemosa and Chaetomorpha) and placed it, along with the naughty Charlize, into a bucket (with tank water obviously). I then disconnected the refugium and set about cleaning it.
Once everything was clean(ish) I added a new layer of mud, refitted the refugium and carefully filled with water. After a while I reintroduced the macro algae and crab. So far so good, however things were about to take an unfortunate downward turn. It seems that by cleaning the refugium and/or replacing the mud I had altered the water chemistry and not in a good way either. The redox value dropped to 250mV and stayed there. Under normal circumstances the redox probe reads somewhere between 350mV to 450mV and to be honest I don't pay that much attention to it. The numbers bounce around depending on whether I've just fed the fish or done a water change. A value of 250mV however was definitely not normal. I wondered if the probe was reading accurately so I cleaned and recalibrated it but still the readings remained low.
A few days after cleaning I noticed some suspicious looking brown algae starting to appear in the refugium and I just knew this wasn't going to be good. Sure enough after about a week or so I started to see signs of it appear in the DT too. It began by coating the gorgonians, the Plexaurella was particularly affected and closed up. Ten days after cleaning I discovered Charlize the hitchhiking crab dead in the refugium. Nooo! I couldn't believe it and felt so terrible guilty. Why did she die? My immediate thought was that the brown algae may have been the cause as some species of dinoflagellates are know to be toxic. I've have not been unfortunate enough to have to deal with this type of algae before but I've certainly read about it a lot. It looked just like typical dinoflagellates, brown and snotty with trapped air bubbles but just to be sure I took a sample and dusted off the microscope.
My suspicions sadly proved correct. The tiny oval protozoans were swimming in a circular motion around an anchor point like a tetherball which is typical of Ostreopsis sp., this is indeed toxic to snails and other herbivorous creatures. I've read many horror stories regarding dinoflagellates in reef tanks, so to say I was feeling depressed was a bit of an understatement, I had visions of all my corals covered with brown snot and the sand littered with shells of dead snails.
According to my research there is no easy way to rid a tank of dinoflagellates and I certainly wasn't keen on the idea of performing a 5-7 day black out. I decided not to panic and continue tank maintenance as normal. I continued with the weekly water changes (yes I know these were not advised) and siphon out as much of the 'snot' as possible in an effort to give the gorgonians a tiny bit of relief. I don't know if it helped them but it certainly made me feel better. In the ensuing days the dinos spread to the tips of the Seriatopora hystrix but surprisingly nothing else seemed affected. Every morning I would count the number of snails to make sure they were all still present and correct.
The redox level remained very low so on the 14th January I sent off a sample of water for ICP analysis just to check if the mud was leeching out something nasty but as you can see from the link below the results looked OK. Nitrates and phosphates were lower than the previous test but not that low.
Since I'd effectively removed most of the beneficial bacteria and critters from the refugium (except for amphipods and mysid shrimps) I decided it might be a good idea to add some diversity back in the form of some live rock rubble. This proved easier said than done as nobody seems to stock actual live rock anymore, it's all artificial or dead rock and bottled bacteria these days. I tried ordering some in from a local shop but when I went to collect it, it was just a bag of dry rock, sigh! In the end I located an online shop that was out of stock but expecting a fresh delivery of Australian live rock in the next few weeks or so. I decided to preorder a small amount and crossed my fingers that it wouldn't take too long.
In the meantime the redox gradually started to creep back up again and by the end of January it had hit 350mV once more, the gorgonians started to pick up again. The first to bounce back was the Muricea followed by the Pinnigorgia and finally after over a month of looking completely dead the Plexaurella shed a layer of algae/mucus and the polyps came back out again, sadly a couple of branches had stripped but at least some of it was still alive. I also only had to frag off one of the Seriatopora branch tips and the rest bounced back in no time at all.
As of today the dinoflagellates have almost completely disappeared from the DT, if you check the Pinnigorgia very closely there is still some evidence of some thin brown strings in one area of low flow but there's not much left at all. I am hoping in another month or so it will have gone altogether, I have my fingers crossed.
Oh and just as things were starting to look up I received acknowledgement that my small order of live rock was available and ready for delivery (20th February 2019). That story will have to wait until another post, oh the stress is never ending....
Hi, my name is Lisa and I live in Derby, UK. I am a self-confessed reefaholic!