Backyard Aquaponics
A place to discuss aquaponics

I am fairly new to aquaponics, a nice xtension of my aquarium days as a kid growing SA Cichlids....
I have a 50 gall drum and a growbed of lava. I have approx 30 Med size Tilapia, I just lost 17 of my larger fish as the water was too dirty;(
lesson learned
I still have slime in the water, when I take out my little glass thermometer, it is covered in a thick slime, light tan color. Any ideas?

You are way over-stocked.. too many fish for the amount of filtration you have...

I't's gunking up your grow ebd.. and resulting in bad water.. killing your fish...

thank you for your reply. how many fish should I have in a 50 gallon Drum?
Any idea what the slime is?

The slime is fish wastes that haven't had a chance to be broken down..

Because your grow bed is too small to provide the level of filtration for the feed rate... number of fish...

How many fish you can stock... is NOT related to the size of the fish tank...

Although IMO... you have too many fish for a 50 gallon drum tank any way...

For a single 50 gallon grow bed... you should only have about 8 fish... growing them to 1lb...

And that's an absolute maximum...

I'm surprised you have any fish left alive...

Hi Kona,

I have a 50 gallon drum for my system and about 50 gallons of grow beds. I have 8 Tilapia in my system that has been running for about5 months now and the fish seem to be doing well and my plants are doing well. I plan to start harvesting fish as they get to the one lb size.

thanks for the info. I bought the whole system from a guy and he delivered it all to me complete. It had 50 fish init. I lost 18 of them last week. They survived in their for about 8 months however b4 I finally had to clean the grow bed.
I guess I need to get another system up and running. Is their any type of solution I can put in the water to control ages and possibly the slime...

are you getting algae on your grow beds?

I had some algae starting to grow on one of my beds and by lowering the level of flooding so that the very top of the gravel is dry it stopped.

Hi Konatyme,

Until you get more growbeds online;

First suggestion would be to stop feeding. The fish will be fine for at least a week or two and it will reduce the wastes.

Put in a Radial Flow Filter (RFF) between the Fish Tank and the growbed. This will allow you to remove some of the waste as solids.

If you have algae in the fish tank - covering it to keep out light will help with most algae. If you've already got a large algae problem then do this gradually over a period of days so you don't get a large die off of algae using up the oxygen.

Add aeration to the fish tank in case there isn't enough.

These things will help but adding more growbeds and a bigger Fish Tank is really a better solution in the long run.

thank you all so very much 4 ur time. My tank is actually a 55 gallon drum. It sure looks allot bigger to me like 100gallons or more, but i called SD drums and tortes and confirmed its size. Have u heard of a swirl filter?

Yep, that will help. Seems like most are leaning toward RFF filters over swirl filters lately. There have been a couple of comments where someone said they noticed the RFF collects more solids. Either will help with your situation.


I mostly refer to anything that holds water and fish as the fish tank, I'm not sure if that's good or bad since that includes IBC's, Blue barrels, Wooden tanks, and a lot of other things. Sometimes I'll get more specific, sorry for the confusion.

Cheers

Thanks Im in need of a life,
(I could help u with that btw)
Could u possibly pt. me to a link on how to build an RFF Filter?

Konatyme

I think the first two videos in this search should work for you Konatyme -

http://www.youtube.com/results?search_query=radial+flow+filter&sm=3

RobBob's uses a 5 gallon bucket which would probably work for you and be inexpensive. RobBob also has a video on cleaning these out posted up on Youtube as well.

This is another video that gave a good explanation from roughly the 1 minute to 3 minute mark

http://www.youtube.com/watch?v=ZUdCtn9mBx8

Here you go.. most of the rest are all based on this...

http://www.earthangroup.com.au/diy-solids-filter/

http://www.earthangroup.com.au/diy-blue ... ow-filter/

Excellent, much clearer with what Rupe posted than in the videos I linked to.