Yesterday I received the results of my latest ICP analysis and I'm relieved to say that the cobalt level has dropped to 1.71ug/l. It's still 17 times above the reference value so there is still a way to go before it's gone completely. I wonder if the drop is the reason for the recent turnaround of my Acropora hyacinthus?
Link to the latest ICP:
Graph showing the ICP cobalt levels since the first test, the rock had been in the tank for 5 months at that point. It's now one week shy of being a year old.
I am generally a patient person but after almost ten months of waiting my patience is wearing thin. ICP analysis has indicated that the tank still has an issue with elevated Cobalt levels. Having discussed my results with other reef tank owners the source of the problem appears to be TMC Eco-reef rock, some have even had it a lot worse than myself, perhaps because they used more rock?
I have sent 5 sample of water off for testing and the Cobalt level has come back as follows:
I have performed 12% water changes every week without fail since the tank was cycled. If the rock had stopped releasing Cobalt or was at least releasing less I'd expect to see the level dropping.
It's hard to tell if or what kind of negative impact the Cobalt could be having on the livestock. I am still struggling with algae issues on the sand, this could be down to all sorts of reasons but I never had an issue with my previous tank set up(s) using good old liverock. The KH level has also begun to rise recently indicating that the corals have stopped growing for some reason. The Red Planet Acropora, A. hyacinthus looks to be holding on by a thread at the moment, it's as brown as I've ever seen it with little to no polyp extension. I get up every morning expecting to find just a stripped skeleton. I also lost Milo my Venus shrimp recently which I am absolutely gutted about. He was completely fine one day, stealing food from the Heliofungia and just gone the next. I have no idea what happened to him, was it a failed moult? His death may be completely unrelated to the Cobalt levels and it could be just one of those things. I really hate not knowing what happened to him.
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.
For this system, for the first time ever, I'm using manmade rock. This is not because I dislike live rock, I really don't. I'm actually one of those rare reefers that loves live rock and all the lovely hitchhikers that come with it (with some exceptions naturally). I found two mantis shrimp in my 7ft tank, awesome critters, anyway I digress. When searching for live rock (in stock or due in stock within a couple of months time) there was none available at all. I agonised about what to do but decided I didn't want to wait an indeterminate amount of time before live rock finally became available again. I decided to try TMC EcoReef rock instead, it looked to be the nicest of the artificial rock choices. I ordered a box of that and will add some of the live rock I already have in the Reefer 170. Of course when Indonesian live rock became available again it was two months too late for me, typical!
This is what you get in box A of TMC EcoReef rock. A few bits had been broken off in transit. In person this stuff is actually quite nice and natural looking. It did smell quite faintly of something chemical, from the paint maybe? More on this subject later.
I must admit it was really rather refreshing to be able to take some time with the rock and glue it together securely, no hastily shoving live rock in to preserve as much of the bacteria/critters as possible. No more worries about falling rocks in this tank either (falling frags yes but not falling rocks, lol). I honestly had very little to do with the aquascape except for mixing of the cement (we used Nyos reef cement and it really was excellent stuff). My eldest son wanted to be involved here and I just let him get on with it. I just stipulated for as many caves/swim throughs for the fish as possible. I'm not keen on super minimalistic rockwork where there is no place for the fish to hide/sleep. I like to think fish are happier with caves and this makes me a happier reefer. There are two separate structures and these were a little higher than I'd like. This tank is not as deep as the reefer so coral placement at the top will need to be thought about quite carefully.
Since I have was going to be transferring over my Yellow wrasse and pistol shrimp/goby pair I needed some sand. I went with Caribsea Seaflor special grade again as I already had some left over from setting up the Reefer. I used a 40lb bag plus the remainder of the old bag. My eldest was very useful here again as he helped to rinse the sand before it went in.
The long slow fill....
Hi, my name is Lisa and I live in Derby, UK. I am a self-confessed reefaholic!