"Mulm" in a reef tank

[Paul B]

I think one of the most important, and least understood or mentioned things in a reef tank is "mulm". That stuff that grows in the dark portions of a tank if it is set up long enough. "Mulm" is a combination of algae, sponges, bacteria, pods, worms, detritus, poop and any thing else that can be propagated or grown in the dark. I realize most people would immediately get out the sponge, razor blade or grenade to remove it but there is a word I like to use to describe those people. That word is "wrong". Mulm is a natural product that you will find in the sea all over the world. Our tanks run on bacteria, algae and a food chain. Bacteria and a food chain are dependent on having a place to reproduce. Mulm is the perfect place. Rocks and glass are flat surfaces that are only two dimensional. Mulm makes these places three dimensional allowing much more space for bacteria and microscopic organisms to grow and do the macarana. (Then love to dance) Pods, which are needed for any small fish also need to eat and their numbers are directly related to how much food they can get their hands on (or whatever pods use to eat with) The more food, the more pods, the more pods, the easier to keep smaller fish. Larger fish such as copperbands and angels also eat pods.
Many people try to keep fish such as pipefish, mandarins or other dragonettes in a sterile tank and while feeding them a couple of times a day with tiger pods or some other expensive food. Those types of fish will not live for long in such a tank and they certainly won't spawn which I consider the "only" criteria to determine the state of health for any paired fish.
Mulm (after a while, maybe a few years) should grow on the back and sides of glass as well as under rocks.
Here in this picture of my clingfish, the mulm appears green. It is really brownish and that fish is on the side of my tank. I brightened up the picture and turned it sideways because it was in the dark and the fish was hard to see.
There is a thick layer of it on the back of my tank where my mandarins and pipefish like to hunt. My long spined urchin also grazes there most of the time as there is not much algae in my tank for him to eat. He is many years old as are the mandarins and pipefish and they are dependent on this food source.
A sterile tank IMO is the biggest problem we have keeping certain fish healthy.
Sterile is good in an operating room but very bad in a tank.



I recently took this off Kauai Hawaii. The rocks are covered in Mulm. You can see a spotted moray eel in the center.



This was in the Caribbean. The mulm provides food for those fry.


This is off a mangrove Island in Key Largo Florida. Notice the growth on the roots.



I know many people will disagree with me. That is fine. But everything I propose I post pictures to back up my theories. None of my ideas come from re-hashed, inside the box rumors.

 

[cracker]

Another thoughtful article Paul.

 

[Paul B]

Whats an "Op"?

 

[cracker]

Op is my term for opinion, never mind the question, . but thanks .

 

[frisbee]

OP can also be an acronym for the "original poster."

Being that I've never been really impressed with the OP's tank to begin with though, I think your "reaching" with this thread. JMO, GL.

 

[Paul B]

I reach with all my threads and am never trying to impress anyone with my tank. It is just the way I like it and it is what it is. But Frisbee I am glad you posted as I like all opinions even if they are not liking my tank.
It certainly is not the nicest tank on here, but it is not supposed to be. It is the longest running though, I think.

 

[cracker]

My " opology's " Gentle men ! I posted a question to Paul then later deleted it ! I was rambling on about sand beds which is an already a well discussed topic. I hope I didn't confuse You guys !
I have a bad pulled rib muscle. The pain killers I got are confusing my brain lol. I should of just left the question. I will stop now before I make things worse !

 

[Paul B]

Cracker. I don't think your question that you deleted has anything to do with anything. It's a fish site and you can post or ask anything you like. I myself can never get upset on a fish site as it is just a hobby and not that important in the world.

 

[Paul B]

That is great, But why are you reading my thread?
King Ding a Ling. (I actually like that)

 

[DaveK]

I could see someone not liking your tank for the aquascape or the methodology behind it. For example, you may not be using enough super models, or the bottles used were exactly the wrong ones.

However, it's really tough to argue with the success you have had with species of fish that are considered extremely difficult to keep. I've got to respect that.

I think one reason some may not like your system is that they don't understand what they are seeing.

 

[Paul B]

Dave, he was correct. my tank doesn't have many SPS corals or very old corals. I can't keep colorful SPS corals because I have to many fish that grew too large and I want them to spawn so I have to overfeed a lot. My nitrates are around 40, to high for many SPS. I don't like SPS either as I prefer LPS. For the last couple of years I have been putting in a lot of gorgonians and sponges. I just find them interesting. That large gorg on the left side of my tank is maybe 15 years old.
I posted a few years ago when I came back from Germany my tank sitter girl allowed the water level to fall about 7" killing all the corals near the top which were mostly SPS. Most of the rest of the SPS died then as the salinity was off the chart. I preferred not to replace them because I am more concerned about fish health and the coral is just there for movement.
These acropora's grew like weeds. The ones that were left continued to grow until my clown gobies spawned every few days on them effectively killing them. You can see her eggs here next to her. I posted these spawnings every week. But I don't really need to make excuses for my tank. It is the way I like it and I was never trying to impress anyone. Plenty of tanks look much nicer and I am jealous of some of them.



The piece that died when the water level dropped was this one. I still have the dead skeleton. It is about 10" across. The parts of it that remained underwater I planted all over the place until my clown gobies found them. I didn't care about the corals because I was excited that the clown gobies were spawning.





There have been 3 accidents in the history of this tank where I lost most of the corals.

 

[DaveK]

In my opinion, there is a lot more to a reef system than how well it looks in pictures. I think you need to consider what is actually being done with the system and what sort of results your getting.

I tend to see people judging on looks alone in such things as tank of the month. I tease a lot about the "DaveK Kiss of Death" because the tank I vote for often doesn't win. Obviously I'm using a different set of standards, not necessarily better, just different.

 

[Paul B]

Dave, my tank was never designed to be a thing of beauty, and apparently it is not. It is and always has been an experiment. I do things to that tank that most people should not do. I am surprised it has not crashed 30 years ago.

 

[rostervandross]

i had two thoughts come to mind when I first read through your post , now I can only remember one but I think it may be worth mentioning. Basically that these mulm deposits in the sea are an ideal environment for all sorts of good stuff as in a tank, but that perhaps in the sea there is an enormous water volume that is constantly refreshing itself so that the mulm does not foul the water like it might do in a closed system.

I am totally on board with you though Paul that it seems many reef aquarium keepers are overly anal and neat freaks about their tanks at the expense of the real health of their system. Vacuuming out every bit of debris and algae, etc. The more I move into natural filtration methods and processes and leave out the filtration products such as chemi pure and carbon in my tank, the better it seems to do in terms of small creatures, pods and the like.

I like the picture of the fish fry, this last time I went swimming in the ocean in Central America several months ago was the first time I had done so since I had gotten into keeping a reef tank and looking at it up close, and I really enjoyed diving down and really looking closely at things, noticing the clouds of fry and lots of familiar fish. It was really just that much more of a blast with a little extra knowledge under my belt to make those kinds of observations.

 

[Paul B]

Rostervandross, thank you for posting. I see that stuff all the time in the sea myself and that started me thinking about it. As I said, the stuff that blows around can be removed, that is not the stuff I am talking about. I am talking about the stuff that grows and is stuck to things. I sometimes blow off the loose stuff but I like to keep this "stuck" stuff as my fish, crabs, and I assume my pods graze on it. Of course we don't want it so thick that it covers our corals. I just want it in the back and under rocks. Maybe this is one reason new tanks are not very healthy.
I also don't use and carbon, Chemi Pure or anything else because I think natural filtration methods such as algae are much better, cheaper and more natural and healthful. There is a reason algae grows in the sea.