What to do with MULM in a fish-less cycle?

Probably should have asked this question forever ago as I’ve been doing this fish-less cycle for a long time now but throughout this process I’ve noticed an accumulation of brown gunk on the substrate/decor (crappy picture for reference)

What is it?
Is it beneficial to the cycling process?

The reason I’m asking now is that 2 days ago after I let my ammonia and nitrite drop to 0ppm each I dosed 2ppm ammonia and had a reading of 0ppm ammonia and 1ppm nitrite after 24 hours. The ammonia processed, great. I waited another 24 hours for nitrite to drop back to 0 ppm. Last night before dosing another 2ppm I used a turkey baster and carefully removed a lot of this brown gunk since the buildup on my SAND substrate was getting kind of excessive. Today, 24 hours after dosing my 2ppm, my ammonia is at 1ppm and nitrite at .5ppm. I added the same amount of ammonia and literally the only difference being is that I removed this brown gunk. My ammonia is not processing as fast as it was and it seems like processing of nitrite may have sped up?

Should I have kept the gunk in there?

After noticing this significant difference I gave the water a slight swirl in hopes to get the remaining gunk into my filters to benefit in some way (1 fluval aqua clear and 1 double head sponge filter) was this the right move?

The one and only time I have seen the brown gunk referenced it was referred to as “ammonia dust” but I don’t know the accuracy of that statement and know literally nothing about it.

Any answers or advice would be greatly appreciated, thank you!

 

Hi Yomiiike
Short answer?
The brown gunk is called mulm. It’s harmless organic material. Very common in all tanks. If you want to know the exact Scientific make up of exactly what is in mulm you are talking to the wrong guy. Gunk is a good name but mulm is another.

In a cycling tank all hard surfaces are a home for bacteria. Even that mulm was a good place to be accordi to the bacteria. It was warm , wet and hard a good food supply.
You made a simple mistake don’t worry about it.

My suggestion is to let the bacteria grow and multiply wherever it wants for now. In a few weeks time you can remove some gunk. Just like the glass it is also a home for bacteria. Don’t clean the glass for the next few weeks.

When the tank is fully cycled in say a months time approximately you can vacuum the mulm OR clean the glass. Not both on the same week.
In a couple of months you could start deep cleaning half the gravel each fortnight ( ish ) . Pushing the vacuum deep into the substrate is how many people decide to keep a tank clean. Deep vacuuming is not compulsory . It’s enough to say for now don’t do it just yet.

To answer your question.
Is it benefial to a cycling tank? Many people like the stuff and would say it is of a big benefit. You don’t have to have it in an established tank but some people are happy with the gunk on display.

 

Hi Yomiiike
Short answer?
The brown gunk is called mulm. It’s harmless organic material. Very common in all tanks. If you want to know the exact Scientific make up of exactly what is in mulm you are talking to the wrong guy. Gunk is a good name but mulm is another.

In a cycling tank all hard surfaces are a home for bacteria. Even that mulm was a good place to be accordi to the bacteria. It was warm , wet and hard a good food supply.
You made a simple mistake don’t worry about it.

My suggestion is to let the bacteria grow and multiply wherever it wants for now. In a few weeks time you can remove some gunk. Just like the glass it is also a home for bacteria. Don’t clean the glass for the next few weeks.

When the tank is fully cycled in say a months time approximately you can vacuum the mulm OR clean the glass. Not both on the same week.
In a couple of months you could start deep cleaning half the gravel each fortnight ( ish ) . Pushing the vacuum deep into the substrate is how many people decide to keep a tank clean. Deep vacuuming is not compulsory . It’s enough to say for now don’t do it just yet.

To answer your question.
Is it benefial to a cycling tank? Many people like the stuff and would say it is of a big benefit. You don’t have to have it in an established tank but some people are happy with the gunk on display.

Thank you so much!
Do you think it would benefit at all giving the water a slight swirl so that the mulm can get into the water column and in the filters? Or would it be better for it to lay dormant at the bottom on top my my sand?

I have a 10 gallon tank that I mistakenly did a fish in cycle and all fish died except for 1 and that tank ended up cycling in 14 days without the use of any bacteria. (I know, I feel crazy even saying that but that’s when all water parameters started showing perfect)

This 40 gallon breeder tank that I currently speak of has been fish-less cycling since May 27th (66 days) with the use of both Tetra Safe Start at the beginning and a bottle of One and Only about halfway through. To say I’m frustrated at this point would be an understatement and I almost feel like putting a bunch of minnows in there and just let it finish as a fish-in cycle but I don’t really want to do that. Hence why I ask if stirring up the mulm would be beneficial as I’m desperate for anything to help this cycle get done.

Doing a fish-less cycle and have an accumulation of mulm on my SAND substrate.

I now know that this is a source for beneficial bacteria to live/feed on and that I should keep it in my tank.

My question is, should I leave all of this mulm dormant on top of my sand substrate that has minimal water flow accessing it?

Or would it be beneficial to give the water a stir from time to time to get this mulm into the water column so that it can get into my filters?

I imagine since either way it is remaining in the tank I can’t really go wrong with either option but don’t know if it would be better to get it in my filters where the bacteria filled mulm will be possibly processing the water better in there?

Thank you!

 

No stirring up the mulm is not going to help . It would likely do more harm than good.

You say the gunk is laying dormant . That’s not true. All hard surfaces are a home for bacteria. They choose where the best spot is to establish themselves. On the substrate is the best spot or on the glass.

Manufacturers would have us believe the bacteria lives on one part of a filter pad ( the biological pad) when in fact bacteria lives on all parts of the filter including the inside and outside of the uplift tubes. All plastic parts including the heater are a potential home. Don’t move the heater or ornaments around or move the gunk around it needs to be stable until cycled. The outside of the heater is maybe a nice warm spot for bacteria? In a few months time you can clean the heater or other glass , but not all of it at once.

I don’t want to sound like a smart donkey but a cycle is never “ done” it’s a living colony ( x2) of bacteria. Old bacteria are dying all the time and new young healthy virulent bacteria are always replacing the old.

One of my tanks has had a pair of failed breeders in it for months and months without any action. Last week I pulled the pair ( couple) out and added 7 dwarf Rainbowfish as a replacement. While the tank was fully established for years I am changing water more often as I am expecting the bacteria to need time to catch up to the new daily bio load ( poop load) . Although I should probably be testing the water I am not even though I know the tank is having a mini cycle most likely. This is to explain that no tank is ever “done” cycling. (Edit . My wife tested it but I had already changed some water)

Short answer.
Stop touching things in the tank.
Stop moving things around.
Unless the nitrates get to be around 160 ppm or the ammonia goes to over 5 ppm by accident don’t do water changes.

Keep adding a little ammonia when or if it falls to zero .
I would suggest ammonia and conditioner are all that should be in the water if and when you change any.

Sorry if I come across as a know it all. I definitely don’t know all there is to learn. The best I can hope for is to learn a little each day.

 

Certainly don't see why an occasional stir would be a bad thing. Don't know how beneficial it would be, but certainly can't see that it would hurt.

 

My question is, should I leave all of this mulm dormant on top of my sand substrate that has minimal water flow accessing it?

You would be surprised how much flow it gets just sitting there on the sand. Additionally if it is left where it is the decomposition processes happen right where the stuff accumulates and not just in the filter.
If you stirr it up you only make your filter clogg faster. Just leave it be.