Who Gives A Fish Forums

I've got a 70 ltr tank, all water tests are perfect, but I was wondering - do I really need to add aquarium plant fertilizer/nutrients?

Depends on various factors - water parameters, plant types, lighting setup, and stocking levels. I personally maintain low-tech tanks and rarely use fertilizers. Check my signature for more info.

The essentials for plant growth, whether on land or in water, boil down to three key elements: light, water, and carbon. These are the fundamental building blocks, and while other nutrients play a crucial role in promoting healthy growth, they're not as vital as these three.

Light is the easy one - it's provided by your aquarium lighting. Water's a given, as your plants are already submerged in it. Carbon, in the form of carbon dioxide, is abundant in both water and air. It's produced by your fish as they breathe, by the filter bacteria as they consume oxygen and release CO2, and it seeps into the water from the air.

Other essential nutrients include nitrogen, which is readily available in your aquarium thanks to fish food and waste. Ammonia, nitrite, and nitrate all provide the nitrogen your plants need to thrive.

Phosphate is another critical nutrient, but it's not typically added to aquariums as it can be detrimental to fish. Phosphorus helps promote root growth and strengthens plant cell walls.

Potassium's also important, particularly for flowering plants - although this isn't typically a concern for aquatic plants.

Iron's a trace element that's commonly supplemented in aquariums, as it's often lacking in water supplies. It plays a vital role in promoting healthy chlorophyll production, which is essential for photosynthesis.

Other trace elements also contribute to plant health, making them more resilient to disease. Think of it like taking a multivitamin - it's not essential, but it can't hurt.

In general, most aquarium plants do just fine with light, water, and the nutrients provided by fish food and waste. If you do decide to add extra nutrients, it's usually a good idea to increase light and CO2 levels to ensure your plants have access to everything they need to thrive.

Thanks Nick and Colin for the info. Just switched to real plants two weeks ago, and so far, so good. Got Anubis calaforatia, Echinodorus bleheri, and another one that looks like Echinodorus Tricolor, but I'm not entirely sure.

As you can see in the photo, I block direct sunlight during the day, but still let some light in for the plants. In the evening, I've got the tank light on for about 4.5 hours. Is this enough light, or should I cover the tank completely during the day?

You don't need to block direct sunlight from reaching your tank, especially with live plants. The extra light will actually help them grow and reduce algae. Since you only have three plants, they won't be using up all the available light.

Anubias isn't a true aquatic plant, so you might want to consider other options. Ambulia, Hygrophilla polysperma and ruba, and more Echinodoras would be great additions. Narrow Vallis and Water Sprite are also good choices – they can thrive in the substrate or on the surface.

Try removing the shade and see how it affects the algae growth. If you notice a lot of green algae on the glass and decorations, you can either reduce the light or add more live plants.

I'm curious about the Anubias not being a true aquatic plant, what do you mean by that? I've always been told direct sunlight on a tank is a recipe for algae disaster, that's why I've got it shaded during the day.

I was once told Blue Stricta wouldn't cut it as a true aquatic plant, that it'd eventually fail in my tank. Fast forward three years and a bunch of pruning sessions, and I'm still waiting for that to happen. My tank relies on fish waste for nutrients, no added ferts. I've got a soft spot for Anubias, works a treat for me.

You can keep Anubias if you like, but it's not designed for underwater life. I view it as a marsh plant that's often sold because it's got tough leaves and doesn't die quickly in water. They grow very slowly underwater, and their leaves are smaller compared to those grown on land.

A simple way to identify true aquatic plants is by seeing if they can stand on their own when out of water. True aquatics have air pockets in their stems that help them float towards the light. They don't have the structure to stand upright outside of water and will collapse under their own weight.

True aquatics include plants like Vallis, Hydrilla, Elodia, Hornwort, and water lilies. Marsh plants, on the other hand, come in two styles: those with rigid stems when grown underwater and those that develop less rigid stems. Some marsh plants, like Zorchzon Swordplants, Hygrophila polysperma, Ambulia, Ludwigia, and Bacopa, have rigid stems out of water but lose that when submerged. Anubias is a marsh plant that keeps its rigid stem underwater.

If I remove the partition, direct sunlight will hit the tank. I've got an 18 watt fluorescent tube for lighting. You're referring to pH, right? I think it was 7.5 last time I checked the water tests.

GH refers to the general hardness of water, which is essentially the amount of dissolved minerals, mainly calcium and magnesium, present in the water.

Your setup seems fine, with the tank positioned on the opposite side of the room from the window, so direct sunlight shouldn't be an issue. I've had tanks placed right next to windows before, receiving direct sunlight for 4-5 hours daily, and I also used fluorescent lights on the tank without encountering any problems.