What is my slightly green tinted tank telling me?

[Corbidorbidoodle]

I've got this 55 gal long, medium light, pretty heavily planted and stocked. It looks perfect from the front, but from the side it's just a little bit tinted green. Like, not "green water" green. It's not cloudy or anything. The first pic is from the end of the tank shooting longways.

I think it may be correlated to fertilizer? Maybe? I feel like it got a little greenish when I started using Easy Green again. It's only been about a week, and the plants are loving it. (you can see the post-dosing growth especially on the plants in the back of the second image)

I don't even necessarily dislike the tint. But I'm trying to understand the hobby more and I'm wondering what the green tint is telling me about what's going on in the water.

There's a bunch of wood in there. I've seen plenty of brown tinting from wood. Is green tinting wood a thing?

[Katherine]

A lot of glass aquariums use slightly tinted glass on the sides. For the first few months after I got mine my kids kept telling me the water was green. They were looking through the side. Nothing wrong with your tank or water.

[Wrencher_Scott]

Interesting, I've never heard of seen green tinted aquarium glass. Are you sure? Why in the world would they do that?

I was thinking it's green algae in the water. But I can't see the pics either. 

[Katherine]

Cory mentioned it in an old live stream when someone asked a similar question (maybe 2 or 3 years old) so that's where I'm getting the info from. A quick Google search says that the green tint is from iron in the glass and that it shows up more in thicker glass so it's likely the sides are made of a thicker glass than the front/back.

ETA: Or possibly the front/back is made from low iron glass and the sides are not, because normally people don't look through the sides as much. Possibly the regular is cheaper than the low iron. *shrug*

Edited March 17, 2022 by Katherine

[Widgets]

It could be a difference in the front vs side glass. It could also be a slight green tint that is more visible due to the deeper water column. If you put some tank water in a white cup, you may be able to see the green tint.

Sometimes I will notice a slight green tint to my water when it It is getting close to (or past) my water change interval. The tint gets much lighter with the water change. I think it is a slight nutrient imbalance that is leading to an algae bloom. If I do the water change I advert the bloom.

[Andy's Fish Den]

I have seen where some companies will use the more expensive low iron glass on the long sides or at least one of them that will be the "front" and then use the cheaper regular glass on the bottom and sides. I'm pretty sure that Marineland did that with their deep dimension series tanks that were in the 150-300 gallon ranges. 

[Biotope Biologist]

Optics is interesting isn’t it! My water looks crystal clear from the front side but if you look in lengthwise you can see the tannic acid tea color from my wood leeching, even after all these years. Unless they add something to the glass that makes the water reflect yellow 🤔

 

You can see the iron in the glass if you look at the pane from the side. Although if it’s dark green I’d imagine it’s FFA. The tint from the iron appears more blue-green to my eyes. 

Edited March 18, 2022 by Biotope Biologist

[Corbidorbidoodle]

So after looking around quite a bit I've decided that the green is just weirdly colored tannin. I had a handful of alder cones in each tank, not for any reason 'cept I've seen other people do it.

But for whatever reason, the water was turning very greenish instead of the brownish I see everywhere else. I've decided that the tannin in combo with a bunch of water lettuce turning the light green and the polycarbonate lids bouncing the green light back in to the tank was just confusing me.

But I took out the cones, changed some water, even added some Purigen bags, and the water is totes crystal clear now.