Backyard Aquaponics
A place to discuss aquaponics

hi Guys, been a while.

Here is a brief background and I will make this SHORT as possible..
What I have...
1. 5000 gallon garden pond (15 catfish in it)
2. 18 sq foot of grow bed (constant flood). 160 gallons according to a formula I ran
3. Red Scorcia as media, about 14 inches deep
4. A 1200 gph pump that brings the water up to the grow bed
and thats it...simple in design, low fish density, wanted to keep it simple and easy and natural looking

Problems I have...
1. thick green sludge in the grow bed.
2. extremely stunted plant growth (been cycling for about 1.3 years now). Really slow and immature growth. never reaches a point that plants fruit or grow big enough to eat. they stay pretty light green too

obviously, my GB is small, but that is why I keep my fish population VERY low. Almost too low in some peoples opinion. Is this the reason for stunted plant growth..? Are the plants not getting enough nutrients? I was thinking of adding another 100 catfish and seeing what happens

Or, is it that I have no air pump and air stones in the GB? Is that why I have the sludge build up and lack of plant growth?

or, is it both reasons??

I just ordered an air pump with 8 lines off of it, so I will have ALOT of air. Do I put the airstones into the fish pond, or actually under all of the red scorcia in the GB?

Any ideas on this stuff guys? thanks so much!!!

hi Guys, been a while.

Here is a brief background and I will make this SHORT as possible..
What I have...
1. 5000 gallon garden pond (15 catfish in it)
2. 18 sq foot of grow bed (constant flood). 160 gallons according to a formula I ran
3. Red Scorcia as media, about 14 inches deep
4. A 1200 gph pump that brings the water up to the grow bed
and thats it...simple in design, low fish density, wanted to keep it simple and easy and natural looking

Problems I have...
1. thick green sludge in the grow bed.
2. extremely stunted plant growth (been cycling for about 1.3 years now). Really slow and immature growth. never reaches a point that plants fruit or grow big enough to eat. they stay pretty light green too

obviously, my GB is small, but that is why I keep my fish population VERY low. Almost too low in some peoples opinion. Is this the reason for stunted plant growth..? Are the plants not getting enough nutrients? I was thinking of adding another 100 catfish and seeing what happens

Or, is it that I have no air pump and air stones in the GB? Is that why I have the sludge build up and lack of plant growth?

or, is it both reasons??

I just ordered an air pump with 8 lines off of it, so I will have ALOT of air. Do I put the airstones into the fish pond, or actually under all of the red scorcia in the GB?

Any ideas on this stuff guys? thanks so much!!!

Have you ever tested your water to see what it looks like? I think you are fine with what you have with the exception of missing some kind of air supply as you stated.

I would test the water and add air to your pond and see what that does. I am pretty new at this AP stuff, but I just put a system together using the basics and have had no issues with plant or fish growth. Tank, Pump, air stone, and grow beds.

Green algae can be a big problem for garden pond systems as the ponds rarely get covered and sunlight and ammonia = algae. I have a bad algae problem in my pond and have to physically remove it regularly.
Also try not to let debris from trees etc to settle in the growbed or pond as this makes the problem much worse
If the algae is using up all your nutrients and oxygen then your growbed plants will suffer

yeah i most definitely remove leaves that fall in.

Its really a thick green algae like SLUDGE that has really taken hold in the grow bed. I am guessing the poor poor plant growth is from this.

If you do put air stones into the GB, how do you keep the thin hoses from getting crushed or cut up by the sharp lava rock...

UGHHH maybe it would be easier to convert the grow bed into a DWC type, or maybe just hundreds of starter cups with hydroton in them and sit them in the GB. (no gravel or media)

You will need the media to host the beneficial bacteria.

Can you restrict the amount of sun which hits the pond? That will help elminiate/reduce the algae growth.

Can you scoop the algae out and let it die? Perhaps once dead adding some back to the pond so it kills off the rest of the algae?

What feed are you giving to your cat fish?

Can you get hold of seasol/maxicrop to help boost your plants? (although I would probably hold off till the algae has died off.

Does adding dead algae back in really kill more algae Arbe. I haven't heard of this but it would be good if it did

I have read (on this forum somewhere) that dead algae releases something which either kills off algae or prevents it from returning.

You can add some fish that eat algae. I had a lot of algae in my tank for a while, and I put a algae eater and a bunch of baby tilapia. Not a sign of algae growth since. I also put some cover over my tanks to limit the sunlight.

do you have any plants in the pond which use the nutrients?

Maybe you have to add a particle filtration into your water supply. either before or after the pump. I don't know whether the green sludge (maybe algae) is something compost worms would like to eat, but if it adds up it might take oxygen away from the roots of your plants, but I don't think gb aeration would change that.

But stick with it, somebody will be able to point you in the right direction.

Cheers

Green sludge in grow bed. Try running it with the water level a bit lower so sunlight does not get to the wet scorcia.

Had you not got the air pump I would have suggested going to flood and drain. If your pond had low DO then it is possible that your plants in the grow bed would have been getting rotten roots which would make for stunted growth. Do the roots to your plants look white or brown (white good). Increasing the DO of the pond water may solve this issue.

Don't add more fish, not with that size grow bed.

Also check the pH of your water. Too high and you may be experience nutrient lock out.

yeah I might try the tilapia, but we have winters here in NC, so I doubt they would survive

I think the algae isnt the problem. no light reaches the water in the grow bed, but the water from the pond is very green. It wasnt like this last year during the summer, so this is new. Not sure why!

I am more concerned with the sludge and zero-stunted plant growth.
Yes I do have alot of plants in my pond, maybe they are using up ALOT of the nutrients? I am definitely going to add 50-100 small catfish, but I still am not sure about how to and where to put these airstones. Do I oxygentate the fish tank itself, or line the grow bed with air stones? if i line the grow bed, How do you keep the lava rock from messing up the tubing or cutting it up, or squishing it.

plant roots are fairly white.

I think the sludge might be the algae from the pond which is being strained out by the scoria.
If your pond went green this year and the sludge got bad this year I'd say the two are related.
Shading the pond would be the only real solution if this is the case.

Put a UV filter on the pond... until the algae clears...