I have a problem with the water in my tank turning green with floating microscopic algae. I've tested the water and the phosphate level is low. I have a good working filter and live plants.
Reaching for my pot of algae control liquid, I see that it says it shouldn't be used where there are live plants. I can reduce the feed levels and maybe increase the frequency of water changes but are there any other ways of ridding the tank of its green water?
It's a 60L tank with a humble community of Leopard Danios, Neon Tetras and an algae eater. I've recently had the sad demise of two good-sized (10cm) Clown Loaches, both within a week of each other. They were about 6 years old.
You may be overstocked, definitely were with the clown loaches, who by the way were small for six years old and haven't lived long as the tank is way too small for them They grow to about 30cm long and should live 20+ years in the right size tank. How many danios and tetras have you and what species is the algae-eater? How often do yo change any water and how much each time? The other thing that makes green water worse is if the tank gets a lot of daylight from a nearby window and/or tank lights are on for too long.
Thanks for your post and comments. I didn't realize that Clown Loaches needed a lot of space so I'll find another species if I re-stock.
I've four Danios and four Neon Tetras. Sorry but I'm not sure what species the Algae Eater is. The fish is about 10-12 cm long and a very distinctive orange colour. The fish is quite active and is happy to move around the tank at most times of the day. That's all the information that I can give you, unfortunately.
Water changes happen every two weeks and I take out about 5L of the total 60L (With ornaments etc. the water volume is probably about 55L) so it's about a 9 or 10% changeover.
The lights are on for about 8 hours a day. The tank is in the proximity of a window but it's north-facing so the tank does not catch much direct sunlight.
As you're doing very small water changes, and only fortnightly, I suspect your nitrate level is high - do you have a liquid-based test kit to test this (and the other crucial water quality tests of ammonia and nitrite)? Weekly water changes of 25% (or anything up to 50%) ought to help considerably.
[ Edited to add: 2 pieces of almost identical advice arriving in stereo from myself and Fishlady. Hope this is helpful. :) ]
Do you have a test kit? If so test for ammonia, nitrite, and nitrate and post the results. I'd bet that the nitrate level is high and that is what is feeding the algae and allowing it to take over. The solution to that is more frequent, larger water changes. Most of us change at least 25% of the water every week to keep the nitrate level low. On the schedule you've mentioned, not enough of the nitrate (which is the end result of the cycle as ammonia from fish waste is converted first to nitrite and then nitrate) is being removed and is available as fertiliser to feed algae growth.
Thanks for all the posts. I followed the link and my algae eater specimen doesn't look like the one shown, which appears to have markings. My algae eater is without markings and is an orange colour. A little more poking around on the internet suggests it could be a Gold (or Golden) Algae Eater (Gyrinocheilos aymonieri).
I do have a test kit and the results show pH 7.4; nitrate 0 ppm; nitrite 0 ppm; ammonia 0 ppm.
I can certainly step up the frequency and % of water replaced.