The algaecide will kill your plants as well - so it's recommended you remove the plants during treatment. Some people may recommend Barley straw - but I think this is most effective on string algae and I'm not sure if it will work in an aquarium setting (it's usually recommended for ponds).

I don't know of any algaecide that is discriminate in what it will take care of (like weedkillers only taking out dicots but not monocots).

Most algaecides are safe for fish - but read the specific labels of the product you use. The more sensitive fish to chemicals are the scaleless fish - like loaches. But I've used algaecides with loaches without any problems. Just follow the directions and don't use more than they advise.

Mollies like salt in their water... so it may be why your mollies died and your platys are still around.

Also - higher wattage can be the cause of your sudden algae bloom.

Skygee-

I DO add salt to my water, according to the instructions on the salt package. Possible its not enough, but I wasn't going for a brackish tank, and I think the mollies were a poor recommendation by the LFS.

And, the green algae problem happened months before I increased the tank wattage. Going up in wattage was an attempt to fix the problem by providing more light for other plants to outcompete the algae.

Frances

I think I've realized that no matter how careful we are about our water, we don't always have the ability to really control the quality. From time to time there are all sorts of weird things that are coming through our tap that are safe to us, but not so safe for the fish and it hits them in some way resulting in illness or death. My brother lost all his fish one time when there was some surge of bacteria in the water. It just wiped out everything he had including 10 year old oscars.

Just something to keep in mind when you know you've been doing everything right and suddenly something throws you for a loop!

I've found mollies do best in a pretty high concentration of salt and do better in a tank strictly for brackish water fish (something LFS never really tell you!)

I think you just need to remove your current stock of live plants, working on just ridding the algae, and then reintroduce the plants. But do realize that the algae will be also probably be resident ON your plants somehow - and ridding yourself of the algae in your tank doesn't mean you're rid of algae completely.

I really love having live plants in a tank, but I've found they're just really a lot of work!! Okay - so I'm a lazy sort of fish keeper. I really like being able to just enjoy the fish swimming around happily without having to deal with planting medium, fertilizing, always having to keep trimming plants, sometimes having to thin things out so other plants get light, keeping algae out, AND keeping water parameters balanced. And then for true planted tanks, they always recommend additional CO2 for the best growth possible. Planted tanks are a lot of work. I used to subscribe to Aquarium Fish mag that has a regular planted tank column. The writer is really very informative.

So while I love looking at a live planted tank with fish - I've been sticking to fake plants in my tanks! Only my pond fish outdoors get plants - and they always wind up eating those.

Hi.. I recently had an EXTEREMLEY bad algae bloom in my tank ( I believe it was caused by a couple pieces of wafers I failed to notce.. because I dont have live plants...). I used a product called Algae Fix. This stuff was incredible. Within a couple hours my tank was crystal clear again ( before you could not see through it). What I did to be safe was look at the amount it recommends to put in.. then I put half. None of my fish were effected. It worked beautifully. Make sure you read the label though because there are certain fish that will die if you use it.. i think its like crustaceans and lobsters... not sure what you have

Algae fix is the best product to use on green water algae blooms and it safe for planted tanks, do check the label as some creatures dont handle the medication. Use extra aeration as the dying algae will take a lot of oxygen out of the water and be ready to change your filter insert too after the treatment.
Limit the amount of light the tanks gets to no more then 8 hours a day until the plants are in and thriving then go to 12-14 hrs a day. It takes alot of plants to out compete algae so be ready to use several live plants! Keep the water clean with regular water changes and watch the light, even reflected light from near by windows can bring on algae blooms, dont overstock or over feed and you should be able to get the water cleared up . It can be a frustrating thing to battle but it can be fixed.

Many thanks for the recommendations for AlgaeFix. It worked astonishingly fast, and I think I got most of the dead algae out by changing the filter cartridges and stuffing the filter box with filter floss to catch it. I've added some anubias, java fern, and apo bulbs so hope I don't have to keep using it. Amazing stuff though. I did move my two shrimp to my other tank though before adding it.

Dollars to donuts the water company adds phosphate too. Get some Phosguard pillows to remove the phosphate or you are fighting a losing battle against algea.

Hi there,

Well the safest thing to do to get rid of green water in an aquarium is to turn the light off. Completely black out your aquarium by covering it with blankets or black garbage bags.....or something to completely block out the light. I realize you said that its not near a window....but if you have lots of windows and light colored walls.....light will bounce....so it has to be completely blocked out.

This will turn the algae brown as it is dying off. You should keep it in the dark for at least a month or more. Then do water changes until the tank is cleaned up, but only about 25% water changes at a time. Take out your java moss but you can leave the fish in if you want.....or move them to your 10 gallon till this is cleaned up. ( after its cycled of course) Its probably best to move them as when the algae dies off it will cause the amonia levels to rise.

As for adding plants, that will help, but you must cover the bottom of your aquarium completely with plants. And only after you get rid of this green water. You will need fast growning plants to start...then evenually you can replace some of the fast growning plants with some that tend to grow slower.

Good luck!!!