UV Filter Question

[grubbsj]

Here is a question to ponder:

During the recent power outages in the NW, we lost 2 tangs, a Power Brown & an Achilles.

The brown we had gotten after he had been in a display tank at a lfs for several months. We had him for about 3 weeks before loosing power. For 5 days we ran off & on a generator. The initial stress seems to have been too much for him, as we were with out power for about 2 hours before getting the generator up and running. He quit eating, and started showing some white spots. We pulled him out and into the medic tank, treated with CU, and bumped the temp to 82. We lost him. None of the other fish in the tank have ever shown any spots.

We chose to replace him with the Achilles. He had only been at the lfs for 3 days when we picked him up. Even though it is suppose to be a herbivore, he was suppose to be eating frozen mices shrimp. Short stay in the medic tank (24 hours, there is no algae there), and into the main tank. We observed a small bit of grazing but not like the work that the Brown put into it. He would not eat the dried seaweed that the Brown ate at all. Nor did he touch any of the other daily offerings. By the end of the week, his color started faiding, then the spots appeared, back to the medic tank, he never ate, and was dead in 2 days.

So, there is still no white spots on any other fish, (green chromes, fire, gobies, 6 line). We have added a UV sterilizer in the return line from the fuge to the tank. If there is any Ich in the tank, this will help. However, we are concerned that by running it 24x7, any pods leaving the fuge will not live through this treatment. We keep the lights on in the fuge 24x7 as well, (we had shortened it to a 12x12 off cycle schedule but this resulted in a large algae bloom in the display, which went away when the fuge went back to 24x7). The Scooter Blenny constantly grazes on the pods & we are on the verge of adding a Mandarin Goby to the tank and do not want to limit the availability of pods from the fuge.

The question, how are you all using your UV filters, and how much “on-time” are you utilizing? Any other comments are appreciated.

Thank you;
Joe

[milesm4]

I have a seperate refegium from my sump I just plumbed it in to the little powerhead that supplies water to the refegium. That way the pods aren't affected and the fish stay fat and happy. Oh and that wind storm sucked I lost power from 330 pm to late the following day.

[grubbsj]

Milesm4, thank you. There is an advantage to a setup with seperate sump & fuge. That may well be happy fish...

Because of space concerns, the sump/fuge is a single, subdivided tank, with adjustable internal baffeles to control the two different flow paths.

[jtReef]

I used my UV filter only when i first setup the tank.
Then I got rid of it.
Currently I only use it in my med tank when adding new fish just for fun.
I say if you are not having any issues in a week or 2 just take it out.
Save the electricity :-) Remember with it you are killing both good and bad bacteria.

[grubbsj]

Other than the two fish which have passed on, there has been no sign of any other problems. It is easy enough to unplug it after a couple of weeks.

Thank you;
Joe

[inwall75]

I unfortunately had to sell my 200g and 75g tank so I gave my UV to a good buddy. It's too much of a pain to use on nano-tanks. With that said, I ran it 24/7 previously.

Bacteria aren't much of an issue for UV whether good or bad because 99~99.9% of them at any point in time are living in a biofilm on the surfaces (glass, LR, sandbed, tubing, heaters, etc) of our tank and will never go through the UV. They are occassionally motile and floating through the water and UV will kill them at that time. (However, we want them to. A bacteria bloom (bacterial floc) can make your water so gray that you can't see into your tank. Whenever someone is having a bacteria bloom, I tell them to get a UV just like I tell people with a phytoplankton bloom which makes the water so green you can't see into your tank). BTW....bacterioplankton makes up so much larger of a portion of a corals daily Carbon budget than most people realize. Beyond that, corals will gladly eat dead bacterioplankton as well. If you want to get further details on this, you need to read Coral Reef Ecology by Yuri Sorokin. Unfortunately, getting this book is getting more difficult every year and they are now up to $500 unless you get lucky enough to find someone who doesn't realize what they have in their hands. I was lucky Coral Reef Ecology; Sorokin, Y.I.; Hardback; World Retail Store - English Books

Pods really aren't affected to the degree that most people think either. Here's a quote by Doctor Adelaide Rhodes of Ocean Pods - Aquacultured Copepods for the hobbyist

Hello - I'm not sure if all pods passing through a UV light will be done in. They actually have very good defenses to UV radiation because they end up in very exposed areas when their tide pools dry up. They have the stamina to crawl across what would be miles to a human being to get to a new pool of water. It has been demonstrated in arctic pods (think of how red Cyclopeeze is) that they can change coloration to combat the oxidation effects of UV radiation. I have recently helped out in a marine lab near my place in Santa Cruz and I placed a filter on the outflow of water which was passed through 2 sand bed filters, 3 canister filters in size ranges from 100 microns to 5 microns, and UV filter - guess what - there were still copepods coming through. We figured there was a leak in the canister filters, and the UV bulb was replaced, I believe to increase the chances of removing any remaining pods. These guys are tough!

Just like the corals in the bacterioplankton situation above, Mandarins, 6-Line Wrasses, etc are as content eating dead pods. So if you lose a few pods to your UV, you aren't starving your tank.

I truly see no downside to running 24/7. If you have a bacteria bloom, it fixes it. If you have a phytoplankton bloom, it fixes it. If barely affects the bacteria population. Motile parasites and problem algal spores are killed by it. The only downside IMO is that it uses electricity and the bulbs should be replaced regularly and the quartz sleeves have to be cleaned regularly.

[grubbsj]

Curt,

Thank you for the links to the information on pods. I'll start looking for the book on line, (if I ever find one for less than $500 US, I'll let you know).

I like the idea of just leaving it on 24x7. (Set it & forget it, until it is time for maintenance.)

As for cleaning the quartz sleeve, the instruction manual for the UV unit I bought indicates that this is an annual event which includes the replacement of the bulb, several shields, & a few gaskets. How often did you clean your quartz sleeve?

Thanks;

Joe

[inwall75]

Originally Posted by grubbsj

Curt,

Thank you for the links to the information on pods. I'll start looking for the book on line, (if I ever find one for less than $500 US, I'll let you know).

Joe,

I'll start looking for a good summary for you if you don't want to buy the book. Sorokin is cited by just about every coral researcher in the world in their papers.

I like the idea of just leaving it on 24x7. (Set it & forget it, until it is time for maintenance.)

As for cleaning the quartz sleeve, the instruction manual for the UV unit I bought indicates that this is an annual event which includes the replacement of the bulb, several shields, & a few gaskets. How often did you clean your quartz sleeve?

First and foremost, even though I'm sure the manual says this, NEVER LOOK AT A UV FILTER THAT IS PLUGGED IN AFTER IT IS TAKEN OUT OF IT'S HOUSING. UNPLUG THAT PUPPY WHEN DOING MAINTENANCE. The equivalent would be looking at the sun with a high powered telescope without UV protection. If you go blind, you can't see your fish tank.

I cleaned the sleeve 4 or 5 times per year.

[grubbsj]

NEVER LOOK AT A UV FILTER THAT IS PLUGGED IN AFTER IT IS TAKEN OUT OF IT'S HOUSING. UNPLUG THAT PUPPY WHEN DOING MAINTENANCE.

This is a good warning to all, and is in the manual, no less than 4 times.

I will add this activity to my quartly cleaning work. Which, at the moment, only has me breaking down & cleaning all of the PHs to ensure that they can still pump water. It is amazing what will grow in the inlet & outlets of PHs.

Thanks;

Joe

[inwall75]

Most people wouldn't really desire this book. It is written by a scientist for scientists. He's the grand daddy of our understanding of coral reefs. He's the person who figured out the role of bacteria in terms of coral food. If you want to understand the nitty gritty details of corals, sandbeds, plankton, the Nitrogen Cycle, bacteria, etc., then this is a good book for you. If you are fairly new to this hobby, remember my second sentence....this was written by a scientist for the scientific field....not hobbiests. When you've been doing this for a few years and think you're pretty smart. Read this book to show yourself just how little you truly know.

Eric Borneman did a write up of some of his research on this link.
http://www.reefs.org/library/talklog...an_051098.html

Indeed, corals do actively feed on bacteria in the mucus, in the water, and attached to particulate matter. They typically utilize them for 5% of their diet, by weight. This is on an efficiency level on par with many of the specialized filter feeders and sponges. Sorokin found that, in general, bacterioplankton ingestion alone can provide from 8-25% of the coral’s respiratory demands. This amount is the equivlent of 1-10% of the animals total biomass per day...from bacterioplankton!! Its assimilation index by nutritional content is the equivalent to the nutrition acquired by the capture of small crustaceans (which are by weight, much greater and a greater energy expenditure to capture). Phosphorus, a normally limiting resource in coral reefs, is found in the cell walls of bacteria. Coral consumption of bacterioplankton provides them with a more easily assimilated source of phosphorous than from the uptake of inorganic phosphate contained in the water.

If you read the whole article, WHICH I HIGHLY RECOMMEND, you can hit [CTRL] F to pull up the "find" dialog box and punch in Sorokin. However, the whole article is based on his work. Eric really brushes over some things in it but there are some things that the boards rarely discuss, AEROBIC denitrification, the fact that there are more than 80 strains of bacteria doing things in our tank, etc. Just in the paragraph I paraphrased above, it shows that corals do not like to capture pods because of the energy expenditure....they like to capture bacteria in mucous nets. Not only that, they "farm and raise" bacteria for their food needs. These things are rarely discussed on the reef boards.