Need help with my low tech tank

Hi,
I'm kind off new to low tech tanks and all the knowledge behind it, especially with plant issues and how to fix them.

I set up a new tank a few weeks ago and some of the plants have turned slightly brownish on their leaves, it doesn't seem like they're dying but at the same time i can't scrape it off like brown algae.



The lights i use came with the tank and the volume is about 57 liters. I dose 0.5 ml tropica specialized fertilizer every other day and don't know if I should change it to after weekly water changes. Any tips or helping ideas?



I'm not sure if these pictures show the browning clearly

 

Hi,

Perhaps green spot algae, perhaps discolouration of the leave. Bit hard to see.

If the plants are new and were propagated emersed (which is typical), plants need at least a month to adapt. Plants undergo a few adaptations to cope with aquatic life. If you drown them abruptly, the coping might be quiet dramatic. The easiest way is just to let them float for a few weeks and then take them fully submersed.

Anyways, 95% of plants issues are related to light intensity and CO2. The less CO2 your water contains, the less tolerant plants are to light intensity. This makes plants prone to light intensity related health issues. They'll sacrifice functions in order to grow. Growth is induced by light intensity; they can't help it.

Hence, growth and health are a little conflicting.

Because you don't inject CO2, there's not much you can do regarding CO2. Which leaves light intensity. If you're using the lights from the box, it is probably much too intense for plants. Try to dim it or block it. This will reduce plant growth (and algae reproduction), but improves plant health.

Regarding fertilisation. You don't need a lot of nutrients as long as CO2 concentration is low. I would conduct a water change (free fertilizers) on day x per week, and perhaps dose some extra 3 or 4 days later.

As long as emersed leaves are green (tripartita), your plants have sufficient access to nutrients.

 

Oh okay, thanks for the tips
I'll try to dim the lights a bit and see if it works.

I'm sorry but english isn't my first language so could you be a bit more clear about the fertilization part?
Don't think I really understood

 

Plants need a lot more CO2 than they need nitrogen and potassium. And they need considerable less of all the other minerals.

Plants that have leaves partly above the water, in the air, have access to a lot of CO2.
Plants with all leaves under the water, have access to a lot less CO2.

1.
If plants with aerial leaves are really green coloured, it means there must be sufficient minerals for all plants, including those fully under water.

2.
If plants with aerial leaves show problems, the cause must be minerals, but never CO2.

3.
If plants with aerial leaves are really green coloured, but the plants with all leaves under water show signs of problems, it is very most likely not mineral related, but CO2.

Hence, the plants with aerial leaves tell you if you have or haven't sufficient minerals in the water.

+++++++++++++

Regarding "I would conduct a water change (free fertilizers) on day x per week, and perhaps dose some extra 3 or 4 days later."

Let's say, you do a water change on sundays (and thereby refill minerals, because tap water contains minerals), you could dose a little extra on wednesdays. But it's not critical. Plants can store minerals anyhow.

 

If Im not clear, feel free to ask. Be as specific as possible.

 

If Im not clear, feel free to ask. Be as specific as possible.

Thanks a lot for the clarification.
I currently dose small amounts of fertilizer every day because I'm a bit scared to dose a lot more once a week because It feels like that could cause and algae problem having that much fertilizer at once. Is that a dumb idea?

 

Plants store excess minerals (typically in another form to avoid toxicity). Hence, the frequency doesn't matter that much, as long as there's enough available.

What is not stored can be used by algae, but:

1) Part of the minerals find their way into the substrate. The substrate has fungi, bacteria and plant roots, but not algae, because algae require light.
2. There are enough minerals in the water for algae, even without the fertilizer. Compared to plants, algae require mega-less minerals.

The most knowledgeable hobbyists of planted tanks I know off, adhere to EI, which means mega-overdosing of minerals along with CO2 injection. There are no algae in their tanks.

In my tanks without CO2 injection, I aim at about 5 grams of fertilizer per 100 liter per week, which equals to 50 ppm of fertilizer. The amount is based on about 25 ppm NO3, which plants require the most. The total amount is higher due to water changes (of course I don't dose just prior to a water change...) and biological activity (recycling) in the tank.

I only dose once a week and I never have algae, ever.

Take-home message:
There is no competition for resources between plants and algae. It is not possible. Algae require a lot less to propogate. A surplus of minerals on its own does not cause algae.

Hobbyist can suppress algae propogation by reducing the light intensity, introducing algae eaters (neocaridina shrimp and snails work great), and plant allelopathy (hence, densely planted tanks works very effectively).

 

Thank you so much, I'm so happy that i can get such good help on this forum

 

I wrote a short article about plant growth versus plant health, in relation to algae:

How to keep plants healthy without growing algae