Another 6 weeks have passed since the last ICP test was performed and I've been eager to know if I have managed to address the tin issue or not. In the intervening period I have performed 7 water changes (14%), swapped out a couple of small pumps that were running the refugium (they came from my previous tank and looked absolutely fine to be honest but I wasn't taking any chances) and run a small amount of Cuprisorb (70ml, the recommended amount for my volume of water) in a reactor for a week prior to sending off the water sample. Apparently as well as being effective against copper Cuprisorb also has the benefit of removing other heavy metals from saltwater so I figured it was worth a try.
The tin levels have fallen by half, yay! Was one of the small refugium pumps to blame after all or has the Cuprisorb adsorbed it (unlikely since it has not changed colour at all) or maybe whatever was leaching the tin into the water has now stopped doing it? I really wish I knew. Still it's on the way down now finally and for that I am really happy. Hopefully in another 6 weeks time the level will have dropped again and maybe even be back down to normal. Fingers crossed for that!
As for the rest of the results, they all look pretty good to me. Iodine is still a little on the low side but it's better than the previous test so one more slight adjustment to the amount dosed and I should hopefully be about there. Frustratingly nitrate is still below the recommended level, I may have to start dosing it at this rate, what an odd thought that is.
It's been 6 weeks since I sent a sample of my tank water off to Triton for ICP analysis. My maintenance routine has been pretty much the same since although I've been changing out slightly more water than usual (12-14% as opposed to 10%, I would perform more if I could but the buckets I use only hold 25l so I can't perform larger water changes easily), I've also been dosing trace elements, in particular iodine as it was undetectable. I thought it was time to see how things stood now.
I was going to use the Triton test again for continuity but discovered that ATI offer a test for RO water in addition to tank water analysis so it was a no brainer for me, ATI was the obvious choice. I have always wanted to know for sure that the RO water I use is without contaminants.
First up is the tank water analysis:
As you can see I still have an issue with tin, if the Triton and ATI ICP machines are compatible then you could say it's dropped a little (from 12.00 to 10.48ug/l) but as far as I'm concerned there is not much change at all. I do have an iodine reading now which is good news it's still low but a lot better than 0 (at least I'm assuming it is, lol). My nitrate and phosphate levels are still low despite feeding, what seems to me, a lot of food. The Siporax and/or refugium appear to be working well, a bit too well it would seem.
Now on to the RO analysis, results below:
I am happy to see that apart from a touch of molybdenum the water looks squeaky clean, not a whiff of tin which is reassuring. Water changes must be helping keep the tin level from rising further but not enough to actually lower the level, I must assume that whatever is leaching the tin that it must still be doing so. Almost all of my equipment is brand new with the exception of a couple of small pumps running the refugium and the pump that I use for water changes. They look fine but I've decided to change them out just in case. I replaced the old glass heater that I used in my water change bucket last month ago as it seemed like an obvious suspect.
As far as the corals go they seem to be doing OK at the moment with no sign of any flesh stripping which apparently can result after long term exposure to a high level of tin. I hope I can find the source and fix it before I reach that point, assuming of course it's not coming from the glass itself in which case I'm stuffed.
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.
Hi, my name is Lisa and I live in Derby, UK. I am a self-confessed reefaholic!