Of all the house plants I’ve grown getting a water garden established has been the most difficult. I tried all sorts of water plants and all I wound up with for my trouble was slimy water.
So I decided to try it another way. I purchased two Biorb aquariums, one 4 gallon, one 16 gallon, with the intent they would be water gardens first and the fish were a secondary concern.
So each tank has a betta, 1 or two African dwarf frogs and the larger has 8 tetras.
I planted both tanks and added fish and all was well. Then the plants started to turn clear, see the couple that are still in the larger tank? The clear leaves on the plants are from a lack of nutrients.
I tested the water the pH was 9! No wonder they couldn’t take up nutrients. So I decided to switch from tap water to bottled water.
Bottled water was worse. In a week both aquariums’ plants were covered in blue green algae and the plants were still dying.
But now the algae is almost gone, the plants are growing like weeds and I expect the tanks to be over grown in a month or so. Here is what I learned.
Plants actually like our hard tap water, fish not so much. But the fish I have and the frogs are doing fine with the hard tap water. I’m using filtered tap water now and plants and fish are happy. Do not use bottled water. There are no nutrients in it, and the blue green algae is a bacteria that appeared when I used the bottled water.
To get rid of chemicals in the tap water I’m using ‘StressCoat’ and ‘StressZyme’ by API. 1 millimeter per gallon of new water.
Plants need fertilizer, especially water plants. I tried the fertilizers you sit under the plants and all the ones I tried turned the water a thick, muddy, brown. The plants are thriving with ‘Flourish’ by Seachem and the water is clear. I put in 1 millimeter twice a week in the 16 gallon tank and 1/3 mill 3 times a week in the 4 gallon tank.
I have an eye dropper that holds one millimeter so that has made adding chemicals easy.
Aquarium plants also like CO2, more than is in the average tank. You can buy CO2 tablets at the fish store, I use 3/4 of one in the 16 gallon and 1/4 one in the 4 gallon tank once a week. The water will be full of bubbles for a few days after but it will clear.
To remove blue-green algae do not use an algaecide. The algaecides do hurt the plants despite claims otherwise. The blue-green algae is really bacteria, not algae, so the algaecide didn’t effect it. I gave each tank one dose of antibiotics. You can get them at the local pet store where they keep all the fish tank chemicals. Since then I’ve been swapping out 1 gallon in each tank daily. It has been 10 days and the algae is just about gone now. There is less each day. Once it is gone I’ll change out the water less often. ( see Plant geek or TFH’s The Planted Tank for more information on aquarium algae and what to do about it. )
I bought some of the bulbs for aquarium plants in the fish store. It took a month of sitting in water on my kitchen counter for 1/3 of them to start to grow. I chucked the rest. The ones that did sprout have done extremely well. One even flowered this week.
The tough plants that survived all my early mistakes and are still with us are: Java fern, water pennywort, red ludwigia repens, Amazon sword plant, and pongol sword.
If you are find the algae is growing but the plants are not use less light and more fertilizer. That seems to straighten things out for me.
I found that no matter what else I do, frequent water changes seems to help the plants more than anything. The more frequently I change the water, the better the plants grow.