How much algae is too much algae?

[Bob Vento]

Ok folks,

I've asked this question to a number of people and get conflicting answers? 

Some say algae is bad for your system, while others say Tilaipia love to eat algae and is part of a
balanced diet.

If I can clearly see the bottom of my fish tank (275 gallon IBC Tote), and the sides are showing signs of algae ... is this a bad or a good thing.

Before I added fish a had a terrible problem with algae but thanks to TCLynx and others ...
by covering the FT to keep sunlight out the algae nearly disappeared and the water was clear again.

When I added the fish last Saturday I uncovered the front half of my tote to allow some sunlight in for the little fish and to begin the algae growing process.

When is enough enough?

What should I watch for? 

Thanks for any recommendations and advice ya'll.

Regards,
Bob

P.S. Finally got some duckweed today and put a little in the fish tank for the tilapia to eat.

[TCLynx]

Surface algae (the green on the sides of the tank) is fine and I wouldn't worry much about that.

Green water (pea soup) that keeps you from seeing the bottom of the tank clearly is a bad thing in aquaponics.

At what point does algae become a problem, well that depends on your goals with the system.

Fish can be raised in green water but keep in mind that green water is steeling the nitrogen from your veggies and algae can cause some extreme pH swings between day and night as well as using up dissolved oxygen over night so do make sure you have supplemental air for your fish over night if you are letting the water run green.

[Carey Ma]

The trick here my friend is that AP is the integration of two almost opposing processes. Greenwater culture is quite common in aquaculture, while in hydroponics, we discourage algae growth. 

I believe that hybrid systems can allow for both provided we are willing to spend the time, money and effort required to operate separate processes i.e. algae scrub, duckweed pond, eliminating light in the veggie grow setup etc.

So my suggestion for you is to continue blocking out the light for you grow-out tank and perhaps allow a little light in to allow for a bit of biodiversity as you are doing now. In other words, keep it simple for now and experiment or expand as your knowledge and money allow. No algae is better than choking with the stuff esp in artificial confinement applications such as IBC.

Personally, I prefer greenwater/ natural pond operation over artificial confinement.

[Bob Vento]

Nope TC,

Water is clear and we can see the details in the tank. It's just the sides that are showing signs of some algae growth and hopefully the fish will consume it off the sides ... so right now all seems good.

Fish are eating, and hiding out in the various tubes provided. Some swim very fast while others don't seem to be in such a hurry.

A lot like people huh?

TCLynx said:

Surface algae (the green on the sides of the tank) is fine and I wouldn't worry much about that.

Green water (pea soup) that keeps you from seeing the bottom of the tank clearly is a bad thing in aquaponics.

At what point does algae become a problem, well that depends on your goals with the system.

Fish can be raised in green water but keep in mind that green water is steeling the nitrogen from your veggies and algae can cause some extreme pH swings between day and night as well as using up dissolved oxygen over night so do make sure you have supplemental air for your fish over night if you are letting the water run green.