algae

[Oliver]

I'm I missing something here (again)? Are we talking about an aquaponics system or an aquarium?

If it is an aquaponics system then you for sure don't want to use a UV light in your water flow path, for it will kill your bacteria. I imagine the same thing would happen to an aquarium as well.

Not good!

Oliver

[rfeiller]

the likelyhood of someone installing a uv system strong enough to do that kind of eradication is pretty slim because of the cost of the equipment. the bulbs are also short lived.

aquaponics water is so full of particulates, slim chance of bacteria or parasites being destroyed as the uv rays would be absorbed by the large particles first. if the water was filtered down to less than 20 microns prior to the uv maybe.

even in full sun a pond can be balanced to the point where very little algae will thrive. i guess it depends on the level of nitrates you need to fuel the system, whither you can allow some of it to be utilized by the algae. then again fish graze on algae and the rotifers that thrive in it.

diatom algae is the pea soup, great for fry, but not so good for the crops.

[Oliver]

While I agree with your assessment about the particles blocking a good deal of the UV, I must say that the whole purpose of a UV sterilizer is to kill bacteria and therefore will be strong enough to do just that.

Remember, aquaponics (if designed properly) is a multi-pass system and at least some of the bacteria will be killed with each pass. The autotrophic bacteria reside mainly in the grow bed/bio-filter area but the heterotrophic bacteria responsible for the mineralization of the solid fish waste remain suspended in the water.

In any case, the purchase of a UV filter for your aquaponics system is a waste of money and installing and using it will be a detriment to your system.

As for the algae, because I raise Tilapia, they tend to eat the algae in the tank unless I feed them enough to prevent them from being hungry enough to go for it. The fingerlings do a better job of keeping the tank clean than do the larger ones.

Oliver

[urbanfarmer]

While I agree with your assessment about the particles blocking a good deal of the UV, I must say that the whole purpose of a UV sterilizer is to kill bacteria and therefore will be strong enough to do just that.

Remember, aquaponics (if designed properly) is a multi-pass system and at least some of the bacteria will be killed with each pass. The autotrophic bacteria reside mainly in the grow bed/bio-filter area but the heterotrophic bacteria responsible for the mineralization of the solid fish waste remain suspended in the water.

In any case, the purchase of a UV filter for your aquaponics system is a waste of money and installing and using it will be a detriment to your system.

As for the algae, because I raise Tilapia, they tend to eat the algae in the tank unless I feed them enough to prevent them from being hungry enough to go for it. The fingerlings do a better job of keeping the tank clean than do the larger ones.

Oliver

Wow! Thank you for that.

[reverse]

What is the effect of green water in a AP system especially in plants? Is this good or bad?

[keith_r]

i'm not sure what you mean by the effect, most systems go through a bloom if exposed to direct sunlight, quite a few go through the bloom even covered,, just make sure you add air if/when your system goes through this phase. when the algae dies off, it releases a chemical that will inhibit another bloom

[Oliver]

What is the effect of green water in a AP system especially in plants? Is this good or bad?

I have a friend who operates a green water Tilapia system. At one time he had about 1000 fish in the tank. I don't recall the tank size. Apparently, the algae absorbed the nitrogen in the system and the Tilapia feed on the algae. He wasn't growing any other plants as I recall. I also believe he wasn't feeding the fish much else. Maybe I'll contact him and get the particulars. He lives near Palm Springs, CA., lower desert and all.

So, to answer your question about the green water effect on the plants, I would say that it will remove some or most of the nitrogen from the system and thereby have less for the plants. This is pure speculation on my part, however.

Oliver

[reverse]

Thanks for the replies that is also what I am thinking, algae bloom will compete with plants(in GB) in terms of nutrients given out by the fish.. I could be wrong though..

But for the fish side of the AP system, I think it is beneficial specialy for fish fries because its food for them..

Fritz

[urbanfarmer]

I have tried growing with green water and having plants. The plants don't grow as vigorously, but they grow. I have only had a problem with iron and nitrogen deficiency. The one time I had a nitrogen problem I just upped the feed a little and threw some urea in the system. I haven't had a problem since (probably because the fish got bigger and the roots of the plants are more established). The iron has been a back and forth battle, but the plants continue to grow. It's a mild deficiency and I am not too worried about it.

Algae that dies and clumps up typically will stick around the roots and other areas in the grow bed. The worms eat it and poop it out and the plants absorb it decomposed from bacteria as well. All I can say is it can work, but a lot more data and research is needed to say why or even how to do it right.

I have heard of farms that use green algae water to fertigate their crops. It acts as a nutrient rich slow release fertilizer. I don't recall the ratio, but I want to say it was 400:1 or something like that.