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....
It's four months since this little tank was set up and all seems to be going really well. Almost a bit too well actually, I'm expecting something to go wrong at any moment, it's usually the way. I'm keeping a close eye on the water parameters now that I have added a few more corals. In the past I have really struggled to keep the alkalinity and calcium levels at appropriate levels even with the use of a calcium reactor and kalkstirrer. As soon as it was pumped in it was sucked up by the corals and clams. This time round I'm hoping to maintain good levels with careful dosing. The parameters today were:
The above were tested using a refractometer, Salifert test kits and a Hanna pocket checker for the phosphate. I'm fairly sure that my phosphate level is not really zero but it must be pretty low and there is very little in the way of nuisance algae growth in the tank apart from a bit of furriness on the rocks. I do not know what the furriness is but it doesn't look too unsightly and stays short. In any case there seems to be less of it now. The macro algae growth in the refugium has been disappointing to date, considering the lack of nutrients I suppose it's not entirely surprising. As long as the reason is not down to a lack of flow or lighting, time will tell, I can't imagine this situation will last for long. I've started dosing a small amount of Reef Roids and KZ Sponge Power recently so they may affect the levels in the future.
You'd think that over 4 months I'd de familiar with all the livestock in my tank, well no actually. A couple of days ago I noticed that the Seriatopora had retracted its polyps and on closer inspection I discovered a small crab sitting at it's base. Where on earth had he suddenly popped up from?? I highly doubt that he came in on any of the SPS frags as they are too small to conceal a crab, I suppose it could have hitched a ride in on the zoanthid rock but the most likely explanation was that it was hidden in the live rock when it was first added. It doesn't look like it's chowing down on coral flesh (at the moment, heh!) so I'll leave it be for the time being and watch and wait. I hope it behaves itself or we'll be having some fun and games with extrication later on.
Day 34: The snails have been hard at work and the rocks are looking clean again. Looks like the coralline is slowly starting to spread too.
Day 26: Oh yes the diatoms are really here now! Time to take the plunge and add a small clean up crew. I do feel a touch nervous as I have no way of knowing if the cycle has actually taken place or not, I've never set up a tank and not been able to follow the progression of ammonia to nitrite and then nitrite to nitrate. Still I'm going to trust that all is well and take the plunge. Two black-footed Trochus and two ceriths were introduced after careful acclimation.
Day 23: I'm finally starting to see a small amount of diatoms on the rock, nothing on the sand yet. Who knew that the appearance of algae in my new tank could fill me with so much excitement, we're on our way! I've still not detected any ammonia or nitrite, did I miss the cycle I wonder?
Day 11: This live rock is exceedingly clean, no hitchikers on it at all. Not so much as a copepod has been found and I've been looking VERY carefully. I'm actually rather disappointed. I just hope that there's some bacteria in there at least, I've been testing for the usual suspects (ammonia, nitrite and nitrate) and so far have only detected 2.5ppm nitrate today.
Day 10: The rocks are now visible (they were the very next day actually). I decided to go with a minimalistic rockscape so that the tank doesn't look too cramped and allow for good flow all round. Clearly I have an issue with the circulation pumps and the sand. These Tunze pumps pack a real punch and the sand just won't stay put. A bit of playing around with the positioning of pumps will be required to find the best location for each of them.
Hi, my name is Lisa and I live in Derby, UK. I am a self-confessed reefaholic!