Saltcorner
By Bob Goemans
By Bob Goemans
Hi Bob,
You have been kind enough to help me in the past and I would appreciate your advice again on various problem(s) I can't seem to solve. I recently had a very nice blue Acropora develop RTN after being in the tank for a few months. Fortunately I didn't lose the entire coral, but a lot of it is now bare skeleton.
The second problem I seem to be having is introducing new fish into the aquarium. Despite my best attempts to cautiously acclimate them, they seem to develop Ick or other stress related disorders and die within a few weeks. What's odd is that I have a group of existing fish that are very stable and have no problem and I have not observed any territorial behavior that would account for fish induced stress.
My tank is a 150 gallon reef with a 45 gallon refugium with plenum that is lit at night. The aquarium's bed is about 1" deep. My ORP runs between 460 - 470. I run a calcium reactor and the dKH is 10 -12. The tank also has a premium protein skimmer and a newer model Eco-Aqualizer. Total water volume of the tank turns over about 12 times per hour. Two Tunze pumps provide alternating and pulsed currents at about 3,000 liters/hr. All parameters are controlled via a computer. Raw water goes through RO/DI filtration 4 stage filter and is integrated into the tank with a float switch. I have a canister filter that I run ESV carbon and ROWAphos.
I generally change the carbon and ROWAphos every month - about 1.5 cups carbon and about one cup of ROWAphos. I feed mysis shrimp and Cyclop-eeze with some Julian Sprung flake food for tangs. I also use DT's live phytoplankton at about 1 oz/ day. Total fish count is less than 10". I use Lugols potassium iodide at about 6 drops per week. Finally for lighting I run two 250 watt metal halides (10K) with two 96 watt PC actinics and two 96 watt PC 10K bulbs. The only thing I don't do is water changes, which might be the problem? I have no measurable levels of NH3, NO2 or NO3 or phosphate. All other trace elements seem to be in the correct ranges by virtue of the calcium reactor.
The RTN seems to be a fluke. No other sps corals have had problems, in fact all seem to be thriving. I was told recently at a local reef store in the Bay area that ROWAphos is now being suspected for RTN by virtue of ultra low phosphate levels or rapid drop in phosphate levels - any truth to this myth?
The fish problems bug me. I have lost two nice fish shortly after introducing both. If you have any thoughts or suggestions as to areas to explore to solve this problem I would greatly appreciate it.
Thanks so much, Greg Vontz
Hi Greg,
Nice to chat with you again. Your water quality appears to be excellent, even though there are no water changes! Nevertheless, I do believe some water changes are appropriate as there are elements and compounds we can not test for that tend to become skewed. And reasonable monthly water changes are the best way to insure they stay within acceptable levels. You may want to read the article by Richard Harker on water quality on my website in the Guest Articles section. As for the coral loss, I wonder about water movement and spectrum/intensity of light in the area where it was placed. Whether that be too much or not enough could affect, sooner or later, any coral addition. How long that takes, and if any tissue damage recently became that specimen that initiated the problem, is impossible for me to judge. And these blooms can become deadly almost overnight! I also suggest carefully checking specimens in the affected area to make sure there are no damaging invertebrate and that water flow and light needs match the species in question. Saving a frag from it and placing it in another area might be the wise thing to do. Luckily, nothing else has been infected.
As for new fish dying, are they quarantined before you receive them? There's a big difference between cautiously acclimating them and quarantining them! And if your dealer doesn't do it, you should. The bigger and more complex the system, the more you have to lose with the "Dump and Pray" method. And if these new fish are not quarantined in your dealers tanks, then very possibly they are already infected from your dealers tank or simply cyanide caught fish that's beyond saving. And as for Ich, your existing fish can be a carrier, however, not susceptible to a major outbreak. Yet the newcomers are another story as they have had their window of opportunity opened in their travels from capture to your tank.. Ich parasites can also be more or less dormant in the sand and just waiting for the right individual to come along that doesn't have the ability to fight it off. Quarantining the new guys is the way to resolve the problem. Easier said than done, but worth it! Check my website for an article on quarantining at the Sea World in uShaka Marine Park in South Africa. It's worth reading!
As for ROWAphos causing a problem, that's shameless dribble in my opinion. I've seen too many reef aquaria using this product, and all are in excellent health. And RTN has been around much longer than this product!
Cheers,
Bob
