Daniel Posted September 1, 2020 Share Posted September 1, 2020 (edited) I have always assumed mulm was some sort of combination of living and dead bacteria. I was always happy to see it because I assumed the mulm is processing fish waste from something more toxic to something less toxic. But that is a least 2 assumptions so far. I haven't googled this yet so I am throwing the question out to the forum. What is mulm? Edited September 1, 2020 by Daniel 2 Link to comment Share on other sites More sharing options...
Brandy Posted September 1, 2020 Share Posted September 1, 2020 I have always considered it to be underwater compost. In my tanks with wood, it is largely wood that has passed thru a snail. Like compost, it contains bacteria, and micro fauna. It is dead plants, fish poop, food bits...bacteria, algae, seed shrimp, detritus worms, etc...depending on how much and how long you leave it there. If, like me, you aren't into gravel vacs, it becomes soil/fertilizer for plants. As an experiment I left a bunch under some wood in the shrimp tank. it disappeared in a short time, like a month? Great plants there now! 1 Link to comment Share on other sites More sharing options...
MickS77 Posted September 1, 2020 Share Posted September 1, 2020 It would be interesting to see mulm under a microscope 🔍 1 Link to comment Share on other sites More sharing options...
Daniel Posted September 1, 2020 Author Share Posted September 1, 2020 Yes, I have had it disappear spontaneously also. It had appeared just as spontaneously in a Daphnia tank that I was feeding green water. No fish, no snails, no plants in this tank. Eventually the hydra in the tank were able to eat almost all the Daphnia, so that point I threw in some hornwort and some guppies and some zebrafish. After that everyday had less mulm than the day before. Now it's almost gone. Link to comment Share on other sites More sharing options...
Administrators Cory Posted September 1, 2020 Administrators Share Posted September 1, 2020 I consider it the build up of debris in the aquarium. A compost pile is probably on par. But depending on the type of tank some might have lots of leaf debris, while an Oscar tank might have a lair of broken down waste. Link to comment Share on other sites More sharing options...
Daniel Posted September 1, 2020 Author Share Posted September 1, 2020 37 minutes ago, MickS77 said: It would be interesting to see mulm under a microscope 🔍 Glad you asked, turns out there are baby cherry shrimp in the mulm (see video that follows). 2 Link to comment Share on other sites More sharing options...
Daniel Posted September 1, 2020 Author Share Posted September 1, 2020 @Cory and @Brandy pretty much nailed it. Seems to be dead plant material, little single celled animals, and even baby cherry shrimp! 13 2 Link to comment Share on other sites More sharing options...
StephenP2003 Posted September 1, 2020 Share Posted September 1, 2020 I was about to break out my cheapo USB microscope before scrolling to this vid. What magnification do you have on it? Link to comment Share on other sites More sharing options...
Daniel Posted September 1, 2020 Author Share Posted September 1, 2020 5 minutes ago, StephenP2003 said: I was about to break out my cheapo USB microscope before scrolling to this vid. What magnification do you have on it? I have a 10x eyepiece and the turret has 4x, 10x and 40x so in the video I start at 40x then go to 100x and finally 400x. I liked the view from 100x the most. 2 Link to comment Share on other sites More sharing options...
KBOzzie59 Posted September 1, 2020 Share Posted September 1, 2020 Excellent work professor! 1 Link to comment Share on other sites More sharing options...
RovingGinger Posted September 1, 2020 Share Posted September 1, 2020 2 hours ago, Daniel said: Glad you asked, turns out there are baby cherry shrimp in the mulm (see video that follows). Well my days of vacuum cleaning are officially over. 4 Link to comment Share on other sites More sharing options...
Alesha Posted September 2, 2020 Share Posted September 2, 2020 4 hours ago, Daniel said: @Cory and @Brandy That was awesome, Daniel! Thank you so much for capturing that video for us. 👍 1 Link to comment Share on other sites More sharing options...
Seized Posted September 2, 2020 Share Posted September 2, 2020 Mulm is almost like a filter in itself. Yes its detritus and debris but its also more than that. Its has very beneficial abilities. Its chock full of bacteria's and nutrients that plants can use up or the bacteria break it down. Mulm is a great part of my aquariums and is honestly a secret weapon in my aquariums. Link to comment Share on other sites More sharing options...
DaveSamsell Posted September 5, 2020 Share Posted September 5, 2020 I consider "mulm" to be a food source for snails 🐌🐌🐌. Really like them in my aquariums. I find snails to be incredibly useful & interesting creatures. Mulm has many benefits, IMO. "Mulm" is also a word that sounds similar, when spelled\spoken backwards. 😊 1 Link to comment Share on other sites More sharing options...
Sliceofnature Posted September 5, 2020 Share Posted September 5, 2020 @Daniel great topic, great video. 1 Link to comment Share on other sites More sharing options...
Terry Ellacott Posted September 25, 2020 Share Posted September 25, 2020 I was given an aquarium for Christmas when I was 10 and an old brass microscope for Christmas when I was 12. I'm now 62 and I'm still looking at the muck in my tanks and it's just as fascinating as it was 50 years ago. Only yesterday I cleaned out an internal power filter sponge into a bowl, let the solids settle out and then put a drop under the microscope. One drop must have had 20 to 30 organisms living in it and there were at least 5 different types. This was a tank that has only been set up for a month with a new filter but I did use lots of Java moss from an established tank and Canadian pond weed from my pond When I have bred fish and used infusoria cultures I have noticed that the creatures that grow are not always the same and some are better than others at growing fish. I don't know their name but if I had ones that looked like cups on a stalk the fry would grow quickly. I would recommend getting yourself a microscope, there are monsters living in your tanks you just don't know about. Mine is so old it doesn't even have a light, it has a mirror to direct the light. I think I've talked myself into asking Father Christmas for a new one which will take pictures. 1 Link to comment Share on other sites More sharing options...
Andy's Fish Den Posted September 25, 2020 Share Posted September 25, 2020 1 hour ago, Terry Ellacott said: I think I've talked myself into asking Father Christmas for a new one which will take pictures. If you haven't already, check out on YouTube "Creative Petkeeping" she recently did an unboxing and review of a microscope that I am thinking of getting myself. 1 Link to comment Share on other sites More sharing options...
Stevefm2003 Posted October 20, 2020 Share Posted October 20, 2020 I have always gravel vac'ed MULM out. Now i am breeding Cherry Shrimp in the tank. Should I delay or abandon the gravel Vac? Link to comment Share on other sites More sharing options...
Stevefm2003 Posted October 20, 2020 Share Posted October 20, 2020 I have always vac the milk out oh the gravel. Now I’m breeding Cherry Shrimp should I stop? Link to comment Share on other sites More sharing options...
Daniel Posted October 20, 2020 Author Share Posted October 20, 2020 As far as I can tell the baby Cherry shrimp like to hang out and feed in the mulm. I think the danger in gravel vacuuming is pulling out baby shrimp and not even realizing it. But you could sort through the detritus in the gravel vac water and see if you find baby shrimp. I had no idea the baby shrimp were in there and wouldn't have known with out some thorough looking through in my post siphoning detritus. 1 Link to comment Share on other sites More sharing options...
Marc Posted October 20, 2020 Share Posted October 20, 2020 I find midge fly larvae in my shrimp tank mulm, free bloodworms for fish in my other tanks. 1 Link to comment Share on other sites More sharing options...
Streetwise Posted October 20, 2020 Share Posted October 20, 2020 (edited) Some of my mulm is from stirring dirt, with more from big pieces of Mopani Wood breaking down and getting grazed, especially by my loaches. My Yo-yo actively digs out holes in the wood for his efficiency apartment. In my tubs, more mulm comes from leaves falling in and getting broken down by snails. Edited October 20, 2020 by Streetwise Link to comment Share on other sites More sharing options...
FriendlyLoach Posted October 20, 2020 Share Posted October 20, 2020 I have plants and so what ever it is, I love it! #STT 1 Link to comment Share on other sites More sharing options...
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