algaecide

[saltydog]

I have an outdoor tank which has had green water ever since the gold fish finished eating all of the plants. I have some Algae Destroyer liquid made by Aquarium Pharmaceuticals. The active ingredient is simazine. It claims "to control the growth of many algae in the aquarium (freshwater)."  It cautions that it is harmful if swallowed by humans & animals. I presume it is safe for fish when dosed as directed. Has anyone else used this stuff? Thanks!

[BigDaddy]

Algaecide should be a four letter word!  YUCK!

Green water can only be removed effectively a couple of ways, diatom filtering, UV sterilization, daphnia or blackout.

I'll assume blackout isn't an option being out of doors (is this an outdoor tank or a pond?).

The goldfish will eat the daphnia.

So, you can either hook up a diatom filter or a UV sterilizer.

Or, you can just let it be and let the green water disappate on its own.

[Nelson]

Algaecide should be a four letter word!  YUCK!

Green water can only be removed effectively a couple of ways, diatom filtering, UV sterilization, daphnia or blackout.

I'll assume blackout isn't an option being out of doors (is this an outdoor tank or a pond?).

The goldfish will eat the daphnia.

So, you can either hook up a diatom filter or a UV sterilizer.

Or, you can just let it be and let the green water disappate on its own.

I visit this site occasionaly and came across a post on algaecides - for your information....Nelson

http://www.aquariumadvice.com/viewforum.php?f=6

"....As for other algaecides, be really careful in choosing one. Many of them are not compatible with pond plants, or at least certain types of plants. A Natural type of algaecide is Barley straw, which can be used as just straw, or pellets made from the straw, or even a liquid barley exctract. I'm using the pellets this year, the water is clear, no algae in the stream, but it's not doing the job with string algae. I have purchased some Algaefix for ponds, but haven't tried it yet. It comes highly recommended from a member here who is a pond professional. Keegan hasn't been to the site for a while, but I trust his advice. "

[saltydog]

Thanks for your input.

The green water has been present for the entire summer.  What would cause it to dissipate on its own?

I tried a diatom filter last year after my apple snails ate all my plants. It's not feasible. I had to recharge it with diatomaceous earth 5 times before the water cleared. And that was after a 50% water change. Stayed kind of clear for about 3 days. Too expensive & too time-consuming!

Can I use a UV sterilizer with my HOB filter? Are you sure this works? My tank gets lots of UV now directly from the sun.

I am talking about really GREEN water. The only way you can SEE the fish is to do a 90% water change. Even after that the fish disappear once they are 3-4" from the glass. It sure looks to me like algaecide is the only option. Any further thoughts?

[gvv]

On early stage of my pond I used Laguna Green Water Clarifier - "...quick acting coagulant that bonds with suspended particles, making them heavy enough to be removed by filtration".
It worked perfectly - no problems with comets or plants. As soon as pond stabilized, I never used it again.

[BigDaddy]

Don't flocculants have the potential to cause gill damage though?

Oh, and the UV the pond gets naturally from the sun is no where near as concentrated as what a UV sterilizer provides.  You will need to buy a pump to run the water through the sterilizer though.

So, this is, in fact, a tank?

How big is this thing?  I can't see how you'd need to change the diatom power 5 times.  My 25 gallon got PEA SOUP green, and once I charged my HOT Magnum with diatom powder (you can't just sprinkle the stuff in, you have to be fairly liberal), it would have my water pristine within minutes.  The amount of diatom powder I used had a direct corrolation to clarity... use a little it takes a while to clear up... use a lot, it clears up within minutes ... LITERALLY.

If this, in fact, is a planted TANK that is outside... the simple fact that you are getting direct lighting is a problem.  If you aren't injecting CO2 into the tank and putting in ferts for the plants, you will continue to get green water over and over and over again.  One solution is UV sterilization.  Even then, you'll probably need a flocculant to make the dead free-floating algae big enough for your filter to catch.

[Sue]

since its a tank, perhaps you could have put a tarp over it to block sun light for a few days after a water change.  Soon cold will slow down the algae.

[saltydog]

Thanks for everyone's input so far. Here is some additional info which has been requested by some of you:

This outdoor tank is a shallow 40G, 30"x30"x14" (lxwxh). It is positioned a few inches from the NNE side of the house so the amount of direct sunlight is minimized. A reflective material is suspended on the westward side of the tank which serves to reduce admission of sunlight in the late afternoon to avoid overheating in July & August.
The original idea for the tank was to make it one where plants would thrive at minimal expense for lighting. Unfortunately, due to my poor choice of animal occupants in the tank, plants have not survived. I did attempt to use a mesh fry cage as a daphnia cage last year but heavy rainfalls caused it to overflow & so lose most of the daphnia several times & I had no success with this method. When the tank water became thick with green water the large diatom filter that I used became clogged with algae every few hours & so constantly needed to be recharged.

Racoons (and cats) have been a problem & I have found it necessary to cover the tank in a secure way to bar their entry. Hoses & external pumps have been rejected as being too tempting for the raccoons to tamper with. Even now they sometimes remove the lid from the HOB filter & jimmy the very tight intake tube sufficiently on a Marineland Emperor 400 so as  to cause the filter to lose suction & thus stop operating.

I have no doubt that the black-out method would work to control the algae but a shroud defeats the idea of having an aquarium to look at from my deck. Without plants to utilize the nutrients in the tank wouldn't the green water reappear in short order after the shroud were lifted?

Barlay straw or pellets seem worth trying. Does anyone know where these might be readily obtained?

I had never heard of a flocculant before but I can see how this might be useful to help rid the tank of water-born algae (alive or dead). I will probably need this even if I go ahead & try the algaecide which I have on hand. Laguna Green Water Clarifier sounds interesting...

I should like to mention that despite the large temperature swings experienced in this tank past & present occupants have been healthy-apple snails, giant danios, gold fish, plecos, & false Siamese algae eaters.  They have all shown excellent growth rates. Gold fish & giant danios have bred prolifically in this tank. (I have developed an appreciation for gold fish now. They do not exhibit the sluggish behaviour that I seemed to remember from my gold fish bowl days as a young lad.) Despite temperatures which occasionally drop to 60 degrees F. the only animals to meet their demise were at the hands of the raccoons. They particularly relished the escargot but were less than enthusiastic consumers of squirming pleco. One bite was enough!

Water changes are a breeze in an outdoor tank as the water can be scooped out with a watering can or siphoned out by means of a hose to water the garden. I use the garden sprayer to clean the filter media (except bio-wheels) & this can be done very efficiently & quickly outdoors.

[BigDaddy]

Try Algone... you can get it at Big Al's