Backyard Aquaponics
A place to discuss aquaponics

I am having a problem with green water.(in the pond, that is)
The fish pond is under 50%laserlite (Opal), but late afternoon it cops a about 3 of hours of direct sunlight.
Several questions;
Do I need to cover the tank completely?
Is it just direct sun or light in general?
Will plants like Papyrus help?
Will duckweed help?
Will snails help?
Are the fish(silvers) at risk?
All comments most welcome
cheers
Rodney

Hey Rodney,
I will try and help and tell you what I can.It is not uncommon for a system to go through two stages of green water/ algal bloom.
Stop feeding the fish, they can survive well and may also clear up some of the algae. Remove any uneaten food or debris from the tank if any. You may add a float to the system which will provide some cover for the water and the plants will also extract some of the nutrients that are excess, the silver perch will also have access to feed as they will eat the organic matter. Lebanese watercress is an excellent plant for this situation.
Do not make too many sudden changes and don't panic. Changing some water is also optional and running the system more than you are now.
Things to check might be number of fish in tank and number of plants in grow bed. You can throw in seeds to fill gaps in the grow beds and thin them when necessary. Good luck Faye

+1

Make sure that you have plenty of air in the water too, and the silvers should be fine. Algae removes oxygen.

Covering the water will help as well, but it does not remove the cause. As soon as you take the cover off, the algae will come back.

Algae needs light and Nitrate. Watch your aeration especially over night as plants and algae may provide O2 during the day but they will use up O2 and provide CO2 at night. This can cause pH swings where the water becomes more and more acidic through the night.

The more you can shade the fish tank, the easier it will be to deal with algae blooms but the real cause is plenty of Nitrate in the water and the most efficient control of that is plenty of plants to use them up.

Thanks Faye and Guys
Just planted my winter seedlings, so the plant situation is a bit lean, thats obviously a contributor, adding a floating duckweed bed tomorrow, then probably an air pump and some in pond plants later in the week. Ph is creeping up but Nitrates and Nitrites both 0.
cheers
Rodney

I've got an idea that algae in a system is could actually be a good thing since it is algae that manufacture the omega 3 and omega 6 fatty acids.

THere are athesthetic and O2 issues but coudl still be a good thing on balance.

Theres probably enough algae if it is just on the walls etc, but if the water is green its too much.

Thanks everyone

went to Shepparton yesterday and bought a pump

The aquarium shop there is fairly big, they had a 1900 lph pump with 4 outlets
I bought that and 2 airstones, about $75 total,blocked off 2 outlets and connected it up
Also got a recycling tub from Bunnings, drilled some holes in the bottom, glued some styro on the sides, now its a floating duckweed bed

This morning its still a bit green, but visibility has improved considerably, so I think I'm on the right track
cheers
Rodney

G'day Rodney. I am guessing by the size and look of your new air pump that it has a diaphram in it....If so blocking off two holes will probably cause backpressure on it, shortening the life of your pump.

Is there a reason you don't want to use 4 air stones and spread the air around the tank abit more?

Thanks Daniel
Yes it is a diapragm pump and
Didn't even think of that because what I have done was suggested by the shop owner, (well she actually said to block off 2 outlets,) I have in fact connected them.
I can get another couple of airstones no probs
thanks

Dan beat me to it.

yep, dont block, and its not surprising to hear retailers giving dodgy advice.............

before i was doing A/C and remembered what it was like to have spare time i used to enjoy giving retailers enough rope to hang themselves with their bullshit. now i just walk out.

Time for an update;
Thanks to all for the input, I took several measures:
Covered the tank, temporary at present, but a hinged craftwood top is planned
Air pump with 4 airstones bubbling away
Floated a duckweed tank, growing strongly
As of today I can see the bottom, silvers looking healthy, and for the first time since inception, I have a positive Nitrate reading, so we must be cycling.
Ammionia and nitrites also up a bit, but a couple of days no feed should help there.
Had a visit from Food &Fish the other day. Milne is a great example of a dedicated practitioner of aquaponics, and a wealth of information. I recommend to all that we visit other setups in our area to get some feedback and ideas.
cheers
Rodney

Gees you could have told you were taking a photo so i could have put my teeth in

just like the gummy look

Just a follow up to my earlier posting (the one before the teeth issue)
Took a Nitrate reading from the pond this morning, and another from the drain
About 2 from the drain and 5 in the pond. Guess that proves that I have some plant take up, just need more plants or bigger
I guess time will provide the balance
Rodney