Water Changes/Green Algae Bloom

[Rouxster]

I'm sure this has probably been asked before, but alas no luck with just browsing or searching. So, I'll just ask specifically.

I have a 5 1/2gal that's been running beautifuly for about 6 months. It has a baby pleco, 2 female guppies and 20 or so grass shrimp.

All the sudden, with no changes by me, I have the dreaded green algae bloom. So, my question is how much water (percentage) and how often do y'all think is safe to do water changes in order to eradicate this?

Thanks,
Micheal

 

[Colin_T]

Can you post a picture of the algal bloom?

Green water and algae problems are caused by too much light or too many nutrients, sometimes both.

The easiest way to treat the problem is to do a 75% water change and gravel clean the substrate each day for a week and reduce the lighting period by an hour or so per day. You can add live plants, especially floating plants, to use the light and nutrients and that will also fix the problem.

 

[Rouxster]

It looks like every other green algae bloom, so just imagine that, lol.

I have a huge bunch of wisteria and I've tried cutting back the light. Even left it off for a couple days.

So, you think 75% a day is okay? Won't be too stressful for the fish? Wow, that's quite a bit I would've thought. Though, thanks for your input

Btw, that your sig file is hilarious!

 

[Lunar Jetman]

Just out of interest, how long are your lights on for each day and is the tank in direct or indirect sunlight at all?

 

[Byron]

If this is a true green water issue, it is caused by a proliferation of unicellular algae. Organics in the water cause it, but obviously light has to be present. But without the organics, it cannot occur. So you need to lessen the organics.

Once you get this cleared up you need to keep it away. More substantial water changes (60-70% once every week normally), vacuuming the substrate in open areas, keeping the filter well rinsed, not over-feeding, not over-crowding...all these affect organics. Organics also occur in the tap water, more than you might think, and in spite of chlorine/chloramine. So assuming everything within the tank was in balance previously, an increase of organics in the tap water could be sufficient to trigger green water. That does not mean to say thee tank itself may not be part of the problem...it could have been teetering on the edge for some time.

 

[Colin_T]

75% water changes are fine as long as the new water has a similar chemistry (ph & GH), and temperature to the tank water. And as long as the new water is free of chlorine/ chloramine before it's added to the tank.

Big water changes dilute things better than small water changes. eg:
If you do a 25% water change each week you leave behind 75% of the bad stuff in the water.
If you do a 50% water change each week you leave behind 50% of the bad stuff in the water.
If you do a 75% water change each week you leave behind 25% of the bad stuff in the water.

A couple of big water changes will make a bigger difference than a number of smaller changes.

 

[Rouxster]

Thanks as always to everyone for all the great info ​

 

[Back in the fold]

Can you post a picture of the algal bloom?

Green water and algae problems are caused by too much light or too many nutrients, sometimes both.

The easiest way to treat the problem is to do a 75% water change and gravel clean the substrate each day for a week and reduce the lighting period by an hour or so per day. You can add live plants, especially floating plants, to use the light and nutrients and that will also fix the problem.

That's the fix plain and simple.