Green water from algae

[crate]

I need help! My cowfish died recently (the last of my fish) and I started to clean the tank out for new fish. The tank had a lot of algae (especially in the sand and on the live rock). I cleaned everything but now the water is green and I can't get it to clear. I did a partial water change and have had the skimmer and filters running for 4 days now (I've been cleaning the filters when needed). I removed the live rock and put it into another tank for now. I've also tried shutting the entire tank down for a couple of days but that didn't help. It's a 75 gallon bow front tank with a 400 Emperor filter and a prism skimmer. Any help will be greatly appreciated.

 

[crate]

I should have mentioned that my nitrite, nitrate, ammonia, and alkalinity levels are all good. Ph is a bit high at 8.5 and specific gravity is at 1.023.

 

[wayne at home]

What do you mean by good - ammonia and nitrite should be zero? Have you tested for phosphate - I would guess you have a 'nutrient' problem. What is your water change regime, how deep substrate, .......

 

[crate]

ammonia and nitrite are zero. I don't have a phospate test. I change about 5 gallons a week and the live sand is a couple of inches thick. How do I get rid of the nutrients if that's the problem?

 

[eykis9]

following is all the info i have abt green water/green algae problems

Green water:
Green unicellular algae will sometimes reproduce so rapidly that the water will turn green. This is commonly called an "algae bloom" and is usually caused by too much light like direct sunlight. An algae bloom can be removed by filtering with micron cartridges or diatom filters. UV sterilizers can prevent the bloom in the first place.

(i don't remember who wrote the following article...)

"Green Water

How to manage Green Water
Other Names: Algae bloom
Color: Green tinted water

Appearance: The water itself turns green. In severe cases the water may be so green that the fish are not visible.

Cause
° Suspended microscopic algae
° Excess light, especially direct sunlight
° Too many fish
° Excess nutrients
° Excess wastes

Green water is usually due to either a significant excess of light (particularly direct sunlight), or a major water quality problem. Although it may look terrible, it is not toxic to fish.

Cure
° Blocking out light completely
° Diatomic or micron filteration
° Introduce daphnia to the tank

Water changes will reduce green water temporarily, but will not elminate it. Completely blocking out all light for three days or more is very effective. The use of a diatomic filter will remove the suspended algae. If daphnia are available, they will quickly eat the microscopic aglae, then in turn be eaten by the fish.

Note: Water aggregators that profess to clump suspended algae and remove it are not effective against green water.

Prevention
° Regular water changes
° Regular aquarium cleaning
° Use of UV Filter
° Avoid direct sunlight on tank
° Avoid overfeeding fish
° Do not overstock the tank

As with any algae, keeping the tank clean and performing regular water changes is one of the best preventative measures. Prompt attention to sudden algae growth will prevent more serious problems."

hope this helps!

 

[wayne at home]

Blocking out light will not do it long term. Not practical. A UV will kill the algae, but the rotting algae will cause a nutrient spike. The answer here is to sort out your nutrients I think?
OK - I think it's nutrients, specifically nitrate and/or phosphate. I'd go to work on the nitrate - do you have any levels. If your sand bed is deep enough, and a couple of inches is, you should have zero , or at least low,(<10) nitrate. I doubt you have - you have recurrent algae problems. How much skimmate are you getting out? What fishload, how much liverock? Are you maintaining your sandbed, does it have any hard, crusty patches?
Sorry if this seems like a lot of questions. I would get a phosphate test kit, and some kind of phospahate remover (ie rowaphos), I'd make sure my skimmer was doing it's thing, and I'd work on my nitrate levels with a series of biweekly 5 gal changes, with maybe one big one at the start. I'd also check my sand bed surface. I\d also look at the advice on algae control on wetwebmedia.com, but I guess much will be similar.

 

[crate]

My nitrites and nitrates are at zero but I do have that crusty stuff on the sand bed that you talk about. I have been tring to mix it around a bit but that just seems to put the crusty stuff lower in the bed. Should I be removing this sand or breaking it up better? I'm going to get a phosphate remover today and start that. I've been blocking the light for a day and it seems to be helping somewhat. As for the skimmer, I was getting a lot out but now I'm not getting as much (since I cleaned out a lot of the algae) but the skimmer is working well. I only have a few live rocks (50 lbs or so) that I was using more for decoration than anything else. I still use the filters and don't expect the live rock and sand to do the bulk of the work. At the moment, the fish load is zero. I'm trying to get the green water problem fixed before adding new fish.

 

[wayne]

I have to go out now, but I'd investigate your sand bed , and read up around that. Also the phosphate remover will help - something has to fuel this algae growth. If you can get it under control maybe you can use a macroalgae to outcompete the greenwater.
Crustiness is not good in a sand bed as it means it cants function so well - you need to research how to get rid of that...

 

[crate]

I finally found the solution, expensive as it was. After checking phosphate levels (they were below .02) and everything else in the tank, I decided to try a diatom filter as eykis9 suggested. It worked to some degree but was unable to clear the green at the bottom of the tank. I returned it and bought a 9 watt Turbo 3X UV sterilizer. I also added some saltwater clarifier (seaclear by Kordon but others make similar stuff). Two days later, I have a clear tank! It cost me about $150 (and I could have gotten cheaper through ebay but I am impatient).

Thanks for all the advice and help. I really appreciate you guys taking the time to help out a newbie.

 

[wayne]

I would think you've fixed the problem, but not at thesource. You've got a clear tank, but why did you get algae in the first place. I still think you've a nutrient problem, and I'd get someone else to double check your nitrate readings