Green Tank

Question
I have a 55 gallon fish tank. I have had it almost 10 years. I have 5 fish in the tank. 2) Irredecent sharks, One is 9 years old and the other is about 5 years old. I have a feeder goldfish, that is 2 years old, a catfish, and a potoctomis ( excuse spelling). My problem is the water keeps turning green. I have to large filters, Marine Land Hot Magnum. They were very expensive. I have to clean the tank at least once a week, and three days later the water turns green. This has been happening for the last 4 months, before then I never had a problem. I took the gravel out thinking this may help. I have 4 aquarium statue rocks in there ( Caves). I use well water in the tank and never had a problem with this. The pet shop suggested not using the lights, but that doesnt help. They also suggested using Kent Freshwater Pro-Clear, but that hasnt help either. Please if you have any suggestions I appreciate it. Thank you.

Answer
Hi Millie!

~Wow, sorry about all your bad luck with green water. I know how frustrating it can be to have a wonderful tank for years and then something suddenly go wrong and ruin it! :(
I can help though!
Bad news~
Taking the gravel out of an tank and trigger many things to go wrong. First of all it will deplete the Beneficial bacteria colonies sometimes greatly. Ammonia might rise in the tank do to this. Also getting all the gravel out will stir up all kinds of debris and will cloud the water for days at a time until it gets back settled. None of this is really important though right now as you've already removed the gravel. Bacteria can become established on the decor and also in your filters as well, but it would be essential that you make sure that ammonia is not present in the aquarium. If so then you should do about at least a 30-50% water change.

~Green water as you probably know can be caused by too much light, and too high a nutrients in the aquarium water. I once had huge amount of trouble with algae so bad in a Oscar cichlid tank that the water would become as green as pure green pea soup. Keeping the lights off didn't do much, and chemicals--no matter what they claimed to do--NEVER did a thing. But you know what cured it in 4 days? WATER CHANGES! I took charge and changed 50% of the water in that Oscar tank every day and in four days, the water was clear and has always been since then.

Changing 50% everyday is a lot of work I know especially in a 55 gallon--But that is the best remedy for this common problem. You can make water changes easy with the Python brand no spill-clean-and-fill water siphon. But be sure to add plenty of good quality water conditioner as you are filling.

~Please try doing everyday 50% water changes for at least a week and keep the lights off as much as you can. I know this is a very frustrating problem but you must be patient and work with it until you get it clear and normal. It will happen! Just keep up with it, that is the important thing to remember! :)

~I hope I was of some help to you! Remember, you can email me again as much as you like on whatever problem you may have! I am more than happy to help you out all I can, Millie!

~Here's wishing you the very best with your Aquarium and Pet fish~

Good luck! Don't give up! Oh, and thanks for taking the time to read my long letter!

Take care, Millie, and happy fishkeeping!
Karen~
Ps: You say your Iridescent sharks are both 9 and 5 years old? They must be full grown then, how big are they? just wondering because so many sources claim so many different sizes that the iridescent sharks will grow to. I love these fish! :) Thanks...