Does it really make a difference?

[davelin315]

I was thinking, the faster the flow through a media reactor, the less contact time there is but on the other hand, more water gets filtered. On the other hand, slower flow means more contact time so the water is scrubbed a little bit more, but less is scrubbed at a time. Doesn't it all even out in the end or are there some things in the water that require more contact time to be filtered out? Also, in using carbon, does having fluidizing it where it's somewhat compact but moving create more dust that could lead to HLLE? Would speeding the water flow through there so that the media is suspended in the water column but contacting other pieces less often decrease the amount of dust produced? Just trying to figure it out because I just installed a fluidized reactor.

[ctenophore]

are there some things in the water that require more contact time to be filtered out?

I think that is the argument for slow flow through carbon reactors. Everything capable of being filtered will be removed with slow flow, but I don't think that there would be anything that specifically requires fast flow for adsorption.

 

Also, in using carbon, does having fluidizing it where it's somewhat compact but moving create more dust that could lead to HLLE?

This is totally new to me. Where did this idea come from?

[davelin315]

When I was looking at it I was thinking that it's rubbing together an awful lot so eventually it would all become smooth and rounded because it's constantly weathering. If it's suspended in the water column and coming into less contact with other granules, then it is less likely to weather and break apart. On the other hand, if the water's moving faster and there are more particles in it, then it will also have the tendency to weather the granules. So, anyone ever do a study on how much fluidity you should have in your media reactor in order to reduce the amount of dust produced? For something that is rounded, it won't make a difference, but for something like carbon which has lots of rough corners and edges, I would think that it would produce more dust by rubbing together a lot at a slower flow rate. Just an educated guess, though, and not sure that the amount of flow and its relationship to the amount of weathering isn't just 6 of one half dozen of the other.

[craby]

I think you want it to percolate a bit, but not so fast that it looks like a BINGO ball tumbler.

Any "dust" should dissipate.

Have you thought of using Rowaphos? If you do, use it sparingly at first so you don't go to zero phosphates all of a sudden and shock the tank.

[CHUBAKAH]

Just trying to figure it out because I just installed a fluidized reactor.

What type did you go with Dave? I just installed one over the weekend myself, and the change just in the look of the water is pretty dramatic considering I was floating already.

 

Everything I have read to date says to go with very little flow, however nothing seems to be very scientific.

 

Tagging along.

[davelin315]

I made my own reactor (it's in my build thread) and am using Black Diamond carbon and have a bucket of phosBgone from dschflier/Filter Fine Aquatics. I've been using carbon for a while but had it in a hang on back filter in my overflow. I'm going to remove that after I install the 2nd fluidized bed filter for the phosphate remover. My own questions about this are based on science, but I have no evidence that it works that way. I was thinking of doing a test by using a coffee filter or something to see how much dust came out of the reactor depending on the flow, but not sure when I would do this.

[reefmontalvo]

I see your point in flow rates. I thought about the same thing here recently. I recently connected a small pump to my reactor and use Rowaphos with carbon. The Rowaphos being under the carbon. I did this cause I was wanted the Rowaphos to compact and not grind its self to a fine dust, as the warning notice said on the inside of the container. Well I do check my reactor daily right before work. I do have a steady flow of about 50g/hr since the pump is rated at a flow of 100g/hr. I have noticed significant changes in both the clarity of the water and the lack of algae growth on the sides of the tank. I have only been doing this now for about two weeks now and I like what I'm seeing. But then every body has there own level of success.

[dschflier]

Great thread.

 

I am really interested in trying to find out what actually causes HLLE. I do see more of it on certain tangs(yellow and hippo) now that I am running carbon. I think if as a group we could figure this out it would be a really great achievment. I am considering buying another yellow tang and putting him in my stand alone acrylic tank. I was thinking of first not running any carbon for 2 months and then running it heavy to see if it develops.

 

Carbon should be run at a slow rate. How slow is hard to say but when large carbon beds are used the water generally just filters through by gravity. Adsorption rate is said to be diffusion rate limited or diffusion controlled. The time is different with different carbons and what you are removing but it takes time for the impurities to diffuse into the carbon. The first 2 steps of adsorption take time. 1st being the water comes into contact with the carbon, 2nd the adsorbates diffuse into the internal pore structure.

 

I have been consistently reducing the water flow through my reactor and my 350 gallons of water looks crystal clear. I will take a look at the flow rate tomorrow to get an idea of what the flow rate is now. I think if you are running it slowly but constantly it may take longer to clear up but will be more effective in the long run. I have not tested this scientifically though.

 

If anyone has any ideas on how to tackle the HLLE problem I would love to be part of trying to figure this one out. I think it is so sad to see such beautiful fish get this. Maybe some scientist type can figure out a method of attacking the problem .

[davelin315]

I have a yellow tang that has it (developed it since I started using carbon on the system months back) but 2 that don't, I also have a unicorn tang that goes back and forth with deterioration of it's head, but not sure if this is attributable to HLLE or not.

[dschflier]

You say you have one that has it and two that dont. Are you saying three different types of tangs or you have 3 yellow tangs? I have three small yellow tangs and I think they all have a mild case of it. I am not sure if the purple is getting some of their fins or they have it a bit. This is why I would like to put one or two alone in my other tank.

[dandy7200]

I use 2 cups/100 gallons and 1x turnover/hour. In my system it equates to 12c carbon and 600gph. It does fluidized in my reactor at this flow rate. I could however put the same amount in a reactor that was made differently and not have it fluidize at all. In my old 54g I ran 2c at 100gph in a cheapo reactor for some time and it did not fluidize as an example.

There are no test kits within the "hobby" budget that can accurately test when the carbon is depleted as a filter medium. I have run carbon on every tank I have ever had and never had a fish with HLLE. Most people suggest the useful life is 1 month. Thats how often I change mine but that doesn't really provide you with any data. My simple observation is that most visible gelbstoff is pulled in the first 48 hours. There is no data I have ever seen published that suggest the dust from carbon can cause any problems in the tank on any level with fish or coral. That said, I've never read anything that suggest a benefit from it either. I run mine through a filter sock and let it roll like a bingo ball tumbler (thanks craby ) and change once a month. If I don't have time to change at the one month interval, I remove the reactor from the system until I have time to reload.

[dschflier]

On that note, If you need any carbon let me know. When you say fluidized, what do you mean? I am not suggesting the carbon causes the HLLE, but in my tanks it does seem to coincide with my carbon use. I wasn't thinking of it as an irritant but maybe it removes a slime coat or something like that. I really have know idea but I would be very interested in figuring it out.

Edited August 13, 2008 by dschflier

[davelin315]

We had a speaker that said that its use has been linked to HLLE when it is fluidized because of the breakdown into dust. Can't remember what justification he had for that or if there were any studies.

 

I have 3 yellow, 1 Pacific Blue, one Unicorn, and 2 Dussumieri (not sure if that's what they are any longer) and 1 yellow has HLLE and the unicorn had a previous condition and it comes and goes. I can't specifically link anything as there are intervening factors in the tank as well, such as the one yellow being the smallest of the trio. I do vary my feeding a lot so I'm thinking it's not nutritionally linked.

[ctenophore]

There is no data I have ever seen published that suggest the dust from carbon can cause any problems in the tank on any level with fish or coral. That said, I've never read anything that suggest a benefit from it either.

 

I read an article about using carbon in ponds, where the author suggested that the carbon dust is extremely effective at rapidly binding organics, after which it is removed mechanically. I thought this idea sounded reasonable, so I gave it a try a few times. I found that the skimmer readily pulls out the dust, and that the water was crystal clear within a few hours. I think the dust helped polish the water faster, but the end result was the same- perfectly clear water in a short period of time. All systems had fish in them and I have not had HLLE problems with any of them. Besides, I thought the consensus was that HLLE was a diet deficiency? Then again, in the late 80's and 90's HLLE was caused by stray voltage which required the use of grounding probes

 

On the topic of Rowaphos, I gave up using that stuff due to the dust it generates. I found that too slow of flow causes it to bind up, and too fast turns it to dust. That dust did seem to cause some problems with acropora but that is very anecdotal. I only use regular GFO and only very sparingly. I haven't replaced the GFO in my mesh bags since January. I like mesh bags over fluid reactors for GFO because it eliminates the tumbling but doesn't allow the stuff to bind up. They are also cheap and easy to change out.

[dbartco]

I have ever seen published that suggest the dust from carbon can cause any problems in the tank on any level with fish or coral. That said, I've never read anything that suggest a benefit from it either.

 

I heard this about dust and HLLE as well. I don't know if it was a speaker we had or someone in the public aquaria that said either. Maybe it was Sanjay at dinner last spring???

 

I have never had and run carbon as well, but rinse VERY well now. I have a black tang that has a mild case that seems to come and go as well. I do feed a large variety, and nori nonetheless. My other tangs have never had.

[dandy7200]

I heard this about dust and HLLE as well. I don't know if it was a speaker we had or someone in the public aquaria that said either. Maybe it was Sanjay at dinner last spring???

 

 

I heard eating peanut butter and jelly sandwiches in front of your fish tank causes HLLE as well.

[jamesbuf]

I heard eating peanut butter and jelly sandwiches in front of your fish tank causes HLLE as well.

 

 

Oh crap, my tank is screwed then. I'm a PB&J fiend!!

[dbartco]

I heard eating peanut butter and jelly sandwiches in front of your fish tank causes HLLE as well.

 

Hey, who knows? I still think carbon is important and beneficial. I wouldn't just blow it off though.

[reefhunter]

I have six tangs and run carbon constantly through a phosban reactor. I have never had a problem but my experience is limited to 18 months...

 

It was a speaker about a year ago who said that the carbon leads to HLLE... I remember it... it was the meeting in Tysons at the scool if I remember correctly...

[dschflier]

This is why I say it would be really interesting to try and figure out what actually causes this problem. People now can raise all kinds of fish in captivity you would think this would not be as difficult to figure out.

[MisterTang]

I guess the problem is that there isn't one underlying factor in any of the cases. If you peruse WWM, Bob Fenner attributes HLLE to everything from stray voltage to light. I have to seriously wonder if it isn't just a general stress-induced disease with all of the causes it's attributed to.

[OUsnakebyte]

I am vaguely recalling an email on the aquarist listserve a while back where Delbeek pointed out a study saying that excessive use of carbon leads to HLLE in fish. Now, I know what your next question is going to be... "well, what defines excessive...?" This is where I have to say that I don't remember at all, but I will try to dig up the email/paper when I get back from PR. I think the gist of the discussion is that you can use too much carbon on a given tank size - but again, I don't recall the details - sorry.

 

In my own experience, years and years ago (geez... is it going on 10..? wow.), I put a filter sock over the drain line from my display and filled it with carbon, thinking I was being all smarty for getting higher flow through my carbon. Well, in about two days my display water was noticeably dark, and there was a fine layer of black soot on the wall of the glass in my sump, and a little in the display. It took me a month of water changes and wiping with a paper towel to get it all gone. Good thing is none of the livestock were worse for the wear...

 

So yes, there can be too much flow over carbon. Where that cutoff is, I can't exactly tell you...

 

Cheers

Mike

Edited August 13, 2008 by OUsnakebyte

[Guest bloodyshoes]

i am new here, but have been running into the same problem with my yellow tang (hlle). the front of his dorsal fin has definately been showing signs of erosion (i read that this is the most common way that yellow tangs manifest hlle). i have been fighting this for the past few months. i stopped running carbon on a phosban reactor for about one month and it seemed to get better and then restarted and it definately got worse. so i have stopped the carbon again and am doing selcon and garlic soaked food (rods, hikari small pellets and nori are the big 3 that i feed). i hope that things haven't progressed to permanent scarring as he is a great fish. there was a good article that i read on hlle (advanced aquarist online), you can do a google search and it comes up that suggests carbon can be a contributing factor although it does also say that vitamin/food issues can also be a cause. i would love to know if anyone has any other ideas. i was thinking about adding multivitamin to the regimen.

 

i will get a picture of the tang tomorrow and post it

[GaryL]

could this be a hereditary condition or some other condition with tangs needing a trace element that no one has discovered yet? and carbon is removing it? there is no doubt that there is a benifit to carbon but too much when not needed? only use for seen chemical warfare?

 

or is there too much of a trace element in our synthetic mixes that could be causing it?

could this be the reason i have seen yellow tangs pricing go up including possible cities(sp?) collection restriction?

 

FWIW

my tangs are always fat and healthy. i feed a variety of foods and add selcon and minced garlic to their food.... then throw the pieces in the tank (maybe 2 or three) the tangs seem to chew on it and spit it out (they dont like it) but always go after it... and i shotgun quarantine them(not recommended)

[jamesbuf]

I run mine through a filter sock and let it roll like a bingo ball tumbler (thanks craby ) and change once a month. If I don't have time to change at the one month interval, I remove the reactor from the system until I have time to reload.

 

 

Just to confirm, you're saying you have the outflow of the reactor going through a filter sock to catch any dust debris? That way you can have more flow through the reactor.