Pond 'mulm' on bottom

[Kayla102968]

Last winter when I had my 300 gallon pond with 6 fish I had little poop or anything accumulate on the bottom...it stayed pretty much clear bottomed.  I changed the water 10% a week and everything was good. 

This winter I have 9 fish in a 700 gallon pond and have a lot of accumulation (almost 2 inches deep in some areas) of green/brown fluffy stuff mixed in with poop.  One question I have is if this is detrimental to the fish and how often should it be removed? I finally did remove it (it was kind of hard since the diameter of the pond is so big that reaching the middle can be difficult). 

I'm also wondering why it never showed up last winter...some thoughts I have are:

1.  The 700 gallon pond has two raised areas at the bottom of the pond and the mulm seems to accumulate on the very bottom of the edge of the raised areas.  I keep the pump on the higher area (so it is not directly on the bottom like it was in the old pond).

2.  It was a warmer winter this year and I fed a new food called Kenzen (which you can feed in colder temps at smaller amounts) so there was only a few days where I didn't feed them this winter...did this cause that much difference in the amount of stuff on the bottom?

 

I still have been doing 10% weekly water changes and the readings have been all 0's this winter (ammonia, nitrite and nitrate).

What is this mulm made up of?  I know there is goldfish poop in it, but it is not attached to the bottom at all...it is just loose and is sucked up off the bottom easily.  The pond has been covered all winter so it isn't vegetation getting into the pond.

 

The other question I have is if I can clean the stuck brown algae off the bottom of the pond (and perhaps the sides) without having to remove the fish.  Is it bad for the fish to have the loose algae floating in the water until it settles where it can be sucked up with a hose?  Can I just scrub the bottom with the fish in there and then wait for the algae to settle to the bottom and then suck it up with a hose?

 

Thanks.

 

[shakaho]

It's detritus.  The best way to remove it is with a retrofit bottom drain that leads to a settling chamber.

 

The fish will be delighted with anything you stir up for them. 

[DieselPlower]

Dead organic matter. Leaves, algae, poop, dirt, etc. I'd suck it out.

[mysterygirl]

I bought a used 5 gal wet vac on Craigslist (ShopVac $10) and vacuum it out.

 

If you keep the nozzle still and close to the bottom, it doesn't stir too much up, but this chore is not the nicest thing for your back. 

 

 One question I have is if this is detrimental to the fish and how often should it be removed?

 

I remove approximately 15 gallons per quarter.  Keep those anti-inflammation pills handy. Ow.

 

1.  The 700 gallon pond has two raised areas at the bottom of the pond and the mulm seems to accumulate on the very bottom of the edge of the raised areas.  I keep the pump on the higher area (so it is not directly on the bottom like it was in the old pond).

 

From what I've read on the net you want your pump to be at the lowest point, and the inflow to be as far away from that as possible, at the other end. 

 

 

2.  It was a warmer winter this year and I fed a new food called Kenzen (which you can feed in colder temps at smaller amounts) so there was only a few days where I didn't feed them this winter...did this cause that much difference in the amount of stuff on the bottom?

 

I don't think so - I feed mine all Winter. Your ammonia readings will be a better indicator of "too much uneaten food". 

 

 

 

 

I still have been doing 10% weekly water changes and the readings have been all 0's this winter (ammonia, nitrite and nitrate).

What is this mulm made up of?  I know there is goldfish poop in it, but it is not attached to the bottom at all...it is just loose and is sucked up off the bottom easily.  The pond has been covered all winter so it isn't vegetation getting into the pond.

 

The other question I have is if I can clean the stuck brown algae off the bottom of the pond (and perhaps the sides) without having to remove the fish.  Is it bad for the fish to have the loose algae floating in the water until it settles where it can be sucked up with a hose?  Can I just scrub the bottom with the fish in there and then wait for the algae to settle to the bottom and then suck it up with a hose?

 

That is impressive, I almost always have a bit of ammonia.

 

Mulm is mostly leaves and plant matter that blows into the pond - flower blossoms too. And fishy poo, dead insects, yuck, don't look to closely.  Even though you say it was covered, if you have that much, it must be getting in somehow.

 

Yes you can vacuum the mulm around the fish. Just be careful -  I get mine to go to the other end of the pond with food, otherwise they are a bit curious.

 

You don't need to scrub the bottom - the ShopVac will pull up what has settled. In fact, you want to do it when it is as settled as can be.  Good luck and don't hesitate to ask more questions.

[Kayla102968]

Thank you everyone for the information and suggestions/ideas

[shakaho]

I have used a shop vac for cleaning, but the fish are always hanging around to eat whatever is stirred up and a fish caught in the vac is a fatality.  Plus the vac needs to be emptied within seconds.  With the bottom area you have it would take hours of backbreaking work.  A siphon works a lot better.  

[mysterygirl]

In my case the pond bottom is lower then where I'd be siphoning to. I ran into the same issue when we had a tank on the floor.

[shakaho]

That's a big advantage of an above ground pond.