Cover Aquariums Evaporation and Algae Experiment

For many years I've been making aquariums with covers and plants growing on top with roots in water - aquarium gardens I call them. Showing it all in hundreds videos, repeating over and over again - planters to reduce water evaporation and to keep water clean and aquarium healthy. Some people get it (thank you all my followers!) - but most people don't. So... I designed a simple experiment, something any one can do at home and...hope it helps more people to have happy aquariums :)

I cover aquariums to reduce water evaporation and to hold land plants growing with roots in water.

 Just like in this a couple years old 1.5 liter glass jar self-feeding sustainable aquarium. 

This aquarium garden has land plants on the top and it's populated with aquatic plants, scuds and tiny snails. 

It looks great and all I have to do is to add water as needed to keep it going like that. 

I have larger size aquariums outfitted in similar ways for growing plants and to preserve water. 

I've been wondering how effective this type of cover is in reducing water evaporation... 

and what difference it would make without land plants... 

Let's check it out!

Here I have 3 glass bottles of the same size with covers. 

Let's remove the cover from the first bottle. 

Use the covers of the other two bottles to make planters or holders if you wish. 

Make a hole in the cover.

Insert a plastic straw in the hole and cut it to a desirable length. 

Make sure the straw fits tightly in the hole. 

I made both covers/ planters exactly the same.

 Now let's fill all three bottles to the same level with dechlorinated aged tap water.

 I use the same type of water in all my aquariums. 

Leave the first bottle open and cover the other two bottles with the planters. 

And put a live plant in the planter of the third bottle.

 So, we will compare the evaporation rate and see what difference the plant makes if any.

 For this experiment I use a plant from one of my 3 liter jar aquarium gardens with fish.

 Put this plant in the third bottle. 

Water evaporates faster from aquariums with larger water surfaces than in these bottles. 

Though, bottles take less space and serve all the same for checking effectiveness of the covers. 

I put all three bottles on a shelf with my aquariums next to the window away from direct sunlight. 

Make sure the water level is the same in all three bottles. 

And the straws are above the water level.

 Mark the water level in each bottle using a permanent marker for references. 

All set and ready on August 12th, 2022 

10 days later on August 22nd 

The water level dropped about 5 mm in the open bottle and in the bottle with the plant. 

September 5th

The water level is 1cm down from the mark in the open bottle.

 No changes in the second bottle. 

And the water is 2 cm down in the bottle with the plant.

 October 18th.

 Two months after the initial set up the water level in the second bottle dropped just about 2 mm or so.

 The plant has lost one leaf - that's what happens when plants are starving without nutrition.

 The cover works really great for reducing water evaporation!

 Yeah! 2mm water level lost in 2 month.

 Compared to 25 mm lost in the first open bottle. 

And 40mm evaporated in the third bottle with the plant - it could be 65 if there was no cover in this bottle! 

Water evaporates from the leaves of the plant in addition to the water surface evaporation. 

Now, let's check for the algae... 

I see a lot of algae deposits on the walls and the bottom of the first open bottle. 

The second bottle has some algae on the bottom. 

And there is some algae on the bottom of the third bottle with the plant.

 December 4th. 

The plant is losing more leaves in about 4 months from the initial setup. 

And water evaporation slows down in the third bottle. 

But look at the deposits of algae in the first and the second bottles!

 The walls of the bottle with the plant remain clean! 

By the end of December 2022 the water level in the first and the third bottles is about the same. 

The water level in the second bottle stays close to the mark - I'm proud of my planters :)

The first bottle looks dirtier than the second bottle. 

I think more dust gets from the air into the open bottle contributing food for algae and adding dirt.

 That is another reason to praise the planters :) 

March 2023.

 It's been 8 months since the initial setup. 

Let's remove the wilted leaves - I still may save this plant by placing it in one of my aquariums. 

This pothos plant did really well for the 8 months long experiment surviving on water only!

 You saw the progression and now you see the end results - all speaks for itself.

 The planters prevent water evaporation and render it to none! 

The growing plants contribute to the water evaporation greatly and keep tanks clean!

 Well, now you have facts and knowledge and it's up to you how to use it. 

Check videos about my aquarium gardens to get some ideas and how's.

 And there is always more than one way to do everything.

 Adding even simple covers like this one works great - I don't add water in my cube aquarium. 

Or take the idea to the next level and make a fully enclosed tank with land plants growing in water. 

The water does not evaporate from this tank and plants make it beautiful and keep the water clean.

Have fun and happy aquarium gardens :)