In a nutshell, do you HAVE to vacuum this up in a low tech tank that has frequent water changes?

I've always been reasonably paranoid about doing so since having intermittent difficulty with cories...well, going moldy (fin rot). I wasn't changing water as frequently back then, but it seemed like my Sterbais would be fine for months and BLAM, cloud of fuzz and dead cory a few days later even with quarantine and medication.

Since I tend to like keeping lots of bottom feeders, is it important for the health of the fish to keep the bottom more clean?

Videos like such:
https://www.youtube.com/watch?v=TzzJ...&feature=share

...seem to imply that Mother Nature is a little behind on her maintenance, but the sheer volume of water change is impossible to replicate.

It's food for the plants.

Who goes through the woods and rakes up all the dead leaves in the forest?

Why would that be beneficial for plants?

Depends on what you call frequent water changes and how much you are changing. Also a sand bottom will allow detritus to be swept to the filter assuming you have enough circulation where a gravel bottom may not. Even then if you do not clean the filters often enough they may be unable to keep up. Finally, how you do clean the tank when it is time can have an affect if you clean the filter and decorations in tap water rather than tank water. That can disrupt your bio-filter and cause issues for fish.

In short though, if you are changing 30% or more water per week and cleaning the filter once a month you should be able to at least keep the fish alive. Rotting vegetation does produce ammonia though so a reasonable amount of circulation is required. My planted tanks require 4 times the maintenance and water changes, just part of the process.

You can clearly see the mulm on the bottom of this tank. The rectangular yellow thing top
center is the flash from the camera. There is not much mulm around the front because the current goes around the left end and across the front left to right. Farther back there
is much less current so the mulm is thicker as you go back. The DHG is small in the left
corner where there is no/not much mulm, but gets bigger as it goes back where mulm is
thicker...more ferts for those plants.
https://www.plantedtank.net/forums/im.../pg_12001e.jpg
My tank "style" is not for everyone. Java moss on back, Fissidens on right wall towards
the top. The W. java fern is just starting to grow as is the Rotala Magenta and
Marcelia Minuto.

How is that for mulm build up


The little white strings under the pond snail and to the left are not roots...

Hello Adam...

This organic material that collects on the bottom dissolves and nourishes the plants. Just follow a sound water change routine by removing and replacing at least half the tank water weekly to remove the nutrients the plants don't use and you'll have no tank problems.

It's all about the water.

B

I totally get the benefit of buildup from the plants perspective, it's the fish's perspective that I'm curious about here.

In the video it shows cories snuffling though a fair layer of detrius. That derius isn't all carried away by the current. It is providing an essentially infinite volume of water change, however, at least in a moving body of water.

I don't keep cories anymore due to losses (5 in 8 months or so, most spaced out), but I do keep quite a few otos. I've gone from water changes of 25% every two weeks (heavily planted Walstad with an AQ20 on a 20L, 50% surface gravel, 50% sand) to 25% every 4 days or so and a ton of flow and filtering (2x AQ50's on the same 20L). Filters cleaned (in tank change water) every month, substrate vacuuming "every now and then"....hence my question.

Haven't lost a fish for a long time due to sickness, so yay, but I'm pretty convinced otos are hardier than sterbai cories once they settle in. Then again, I may just know them better now.

Keep in mind our definition of "clean" is totally out of line with what nature calls "clean". We need to keep the water from being polluted rather than keep the tank "clean".
There are many different ways to do this. One is change more water more often and another is to do a more complete job of cleaning up debris., including the filter, which lets us do less water changing as there is less debris to degrade into ammonia, etc.
Catfish are especially involved with living in the sludge on the bottom in nature and it does not harm them in our tanks. Pollution does!
Solve the pollution in either way and then "clean" as your mindset feels right.

What bottom snufflers are you folks keeping in those tanks?

Bump: I like this, thanks!

As a side bit, I have cories in a ten gallon where there are lots of unwanted unkept plants. the plants are in all stages of dying/ dead to thriving. I keep them in this tank as a type of cover for small fish and they also act as food for fry. The cories find lots of piles of small debris in the corners and around the rocks and seem to love hunting for bits of food in the junk. It is a tank where fish go to be safe while they grow bigger. As a small tank, I find I do need to do lots more water changing than I might on larger tanks but then it is handy to do a ten and it does set on top of my reserve water barrel.

Having two no-tech 20G heavily planted tanks, vacuum impossible.
There is no where to touch down the tube on the substrate.

Water changes based on NO3 levels only.
About 8 gallons every 2-3 weeks keeps it in line.

For me the detritus & mulm build up inside my sump. I clean it out about every month sometimes there up to and inch of it below my bio balls. It also gets in my pumps prefilter and they need to be clean up to. I see very little in the tank except around the bottom of plants. I take a small hose a clean around them once every couple weeks. I would say that detritus & mulm are sign of a healthy tank.

I've had some tanks running for over 5 years with no vacuuming. I think it really boils down to aesthetic more than anything. I keep many cory catfish in a 55 gallon tank that is very full of mum.