In my quest to discover why some of my corals were looking pale (in one case very pale indeed) with poor or non existent polyp extension I decided to send a sample of tank water off to Triton for an ICP-OES (which stands for Inductively Coupled Plasma-Atomic Emission Spectroscopy) analysis. I must admit that I had actually intended to do this anyway when the tank reached the 6 month mark just because I was curious as to what it would tell me about my water quality.
At the same time as sending off the sample I did a whole round of testing myself. The intention being that I could compare both results and see if my test kits (not to mention my testing technique) were up to scratch.
Here are the results from my testing performed on the 18th April 2017.
Specific gravity: 1.026 (51.7mS according to my conductivity probe)
Alkalinity: 7.0dKH (Salifert)
Calcium: 410ppm (Salifert)
Magnesium: 1272ppm (Salifert)
Potassium: 390ppm (Salifert)
Strontium: 0-3 (Salifert)
Nitrate: undetecable (Salifert)
Phosphate: undetectable (Hanna phosphate)
Iodide: <0.01 (Salifert)
Iodate: <0.03 (Salifert)
...and here are the ICO-OES results.
So what do the above results tell me? Well, the obvious issue that immediately jumps out is the elevated tin (Sn) level. Eeek! Where on earth did that come from? I have read that a possible source for tin could be the glass (as molten tin is used to "float" the glass on during it's manufacture). Other than that, something could be rusty and contaminating the system but I'm at a loss as to what it could be, all the equipment was bought new and there's nothing obviously rusting as far as I can see.
Apart from tin, I don't think the rest of the results look too bad really, pretty much as I expected. My tests are not that far off which is good to know (with the possible exception of Strontium which is low with the Salifert test kit but actually at an acceptable level according to Triton). My phosphate level is surprisingly low despite the increased fish load and extra feedings. Triton recommends feeding more and/or reducing the amount of phosphate remover used. As I don't use any remover that's going to be difficult to do but I do intend to feed more to my corals.
Ca: 410 434
Mg: 1272 1258
K: 390 386
Sr: 0-3 7.06
Iodide/Iodate: <0.01/0.03 0
PO4: undetectable 0.006
So what now? Well I'm going to continue performing water changes as normal, maybe change out a little more in the next a few weeks. Triton recommends 6 x 15%, but they are probably assuming that I don't perform water changes at all which is certainly not the case. I popped a polyfilter into the sump for good measure mainly because I had one to hand (from years ago, I hope they don't 'go off'?) and surely it can't hurt. I also intend to start dosing iodine again.
Just before sending off the water sample to Triton as reported in a previous post, I also reduced the intensity of my lighting. It's been 14 days now and I do think that there has been an improvement in the corals, the colours look a tiny bit better and the polyps are starting to extend again. Perhaps the lighting was the main issue? I am hopeful that things will continue to improve. Now I just need to get rid of all that tin....
Photos to follow on Monday with the full May update.
For a while now some of the corals have been losing colour. The worst affected being Acropora #3 (A. formosa?), the one that has been recovering from blistered skin. It's reached a point where some form of action needed to be taken. I had hoped that by introducing some more fish the nutrient levels would increase and the corals would look a bit happier, but even though I'm adding a lot more food to the tank the nitrate and phosphate levels still remain oddly undetectable. I performed as many tests as I could on Friday (with the exception of Iodine) and the results were as follows.
Specific gravity: 1.026
The levels are a touch lower than I'd really like them to be especially alkalinity and Strontium but the Tropic Marin Pro Reef salt mixes up to give an alkalinity level of 6.7dkH and 0-3ppm respectively so if I want those levels to increase I'm going to have to supplement them in my mixing bucket before doing a water change.
I intend to add Reef-Roids to feed the corals more frequently as the filtration system I have in place seems able to cope with the extra loading. Along side that I also decided to alter my lighting schedule. I looked at some of the other LX7 lighting profiles posted on the GHL website and their levels were set lower than mine. Had I been unintentionally frying my corals with too much light I wonder? So now I have reduced the levels and the difference is quite noticeable to my eye, the tank looks a lot darker and quite a lot more bluer! To be honest I really don't like the look but if the corals respond positively then that's what counts. I expect I'll get used to it eventually.
Two days ago, after what seemed like an interminable wait, my lighting unit was finally delivered. Yeeesss, Christmas came two days early for me that's for sure! The GHL Mitras LX7 is one sweet looking lighting unit. Needless to say I wanted it up and running asap (I mean come on the tank has been without a decent light for 10 whole weeks!!) so a quick trip out to purchase some wall brackets was required and then yesterday (after working myself up to it) came the stressful bit of hanging it up over the tank. It was at this point that I really wished that I'd waited to start up the tank and add some little fish. Visions of it (or the drill) falling into the tank and blowing up flashed through my head. Anyway to my very great relief all went well, no smashed tank (or dead fish thank goodness!) and there's no way that light is going to fall down any time soon. We've left the hanging wires long for the moment in case we need to adjust the height of the light in few days time.
If I thought that getting the light up there was the hard bit then I was way off, that was a doddle compared to working out how to programme a lighting schedule. There are so many options on the Mitras that it's really quite daunting. I think we have it down for now, no doubt the odd tweak may be required in the future. Wow this light is bright! I'm thinking that the algae growth in the display tank will go into overdrive now, eek! I hope the CUC are prepared.
The biggest downside to the lights is the fact that I can't take photos with my iphone anymore, the shots come out very strange looking with odd lines on them. Darn it! Back to my trusty DSLR then but even that has problems with the white balance. I'll need to sort out the settings asap.
I can't wait to go out and get some corals now.
The tank is now just under 10 weeks old and all the equipment is finally up and running bar the dosing pump for Balling salts (that's going to have to wait a while as I'm currently penniless at the moment).
The sump has changed quite a bit since the initial set up photos were taken. Within it now resides a Deltec SC1351 skimmer, a Schego 200W titanium heater, a Tunze 1073.02 return pump and the sensor for the Reefloat ATU-pro3. Additionally it now contains siporax in three separate baskets, two in the sump and one in the old ATU tank. Altogether they contain 5l of media and will be cleaned on an alternate basis to minimise disruption to the bacterial colonies. To the left of the sump sits a DIY refugium, it's a bit of an odd shape, tall and narrow, it remains to be see if it will grow algae efficiently or not. It is lit by a Beamswork Evo 6500K 18W LED on a reverse cycle to the display tank. Presently it contains a layer of Tropic Marin reef mud and a variety of macro algae (Cauperpa prolifera, Caulerpa serrulata, Chaetomorpha and a tiny bit of C. racemosa that sneaked in with the Chaeto). Both the refugium and the old ATU tank are supplied with water from the overflow via a small Eheim pump, they have been fitted with bulkheads to allow the water to flow back down into the sump and up to the display tank (DT) via the return pump.
I have removed the filter sock and to begin with I ran the tank without any form of mechanical filtration. Recently however I decided to add a bit of filter floss as I was starting to see increased levels of particulate matter in the DT.
The electrical sockets are sited away from the tank in a cabinet to the left, along with the RO reservoir for the ATU.
Hi, my name is Lisa and I live in Derby, UK. I am a self-confessed reefaholic!