Plant leaves dying… What to do?

I have some live plants in my fish tank and some of them seem to be dying. One of them thats losing leaves and rotting (idk if that’s the right word) is new, I had it for a week or 2 so far.

The ones at the bottom are also going a little bit yellow and I’ve had them for a while.

The temperature is 78 and I dose it with fertilizer every week.

Which plants are you concerned about, there's a lot in the tank?

Some aquarium plants are grown out of water and when you put them in an aquarium, the terrestrial leaves die and new aquatic leaves grow.

Some plants sold for aquariums are actually garden plants that die when kept under water.

Water lilies and lotus can have red or brown on their leaves as part of their colouration. If the leaf is soft and mushy, it's rotting but if the leaf is firm, it could be natural colours.

Colin_T said:

Which plants are you concerned about, there's a lot in the tank?

Some aquarium plants are grown out of water and when you put them in an aquarium, the terrestrial leaves die and new aquatic leaves grow.

Some plants sold for aquariums are actually garden plants that die when kept under water.

Water lilies and lotus can have red or brown on their leaves as part of their colouration. If the leaf is soft and mushy, it's rotting but if the leaf is firm, it could be natural colours.

Click to expand...

I couldn't get a good photo of it but it was a couple of leaves on the second photo! Thanks for the advice thou

If you have recently bought these plants what you are experiencing is the terrestrial leaves dying off making way for the aquatic leaves. Do not throw the stalks or any part of the plant away as it will grow back.

The small plants closest to the substrate in the second photo are a species of Echinodorus. I agree they are not looking good, but this can be due to more than one factor.

How long have you had them, as asked by itiwhetu? And what exactly is the "fertilizer" you are using? Light is another factor, especially since these plants are as far down in the tank as possible so light will be weaker. This light issue may not be the issue, the other two things are involved.

I do agree with Bryon looks like lack of nutrients. You can use two types of fertilizer root tabs and liquid fertilizer. I would recommend root tabs for this case. Since it would target the plant directly and not other plants. It could also be light maybe keep the lights on an extra 1-2 hours for a week or two to see if it makes a difference.

Byron said:

The small plants closest to the substrate in the second photo are a species of Echinodorus. I agree they are not looking good, but this can be due to more than one factor.

How long have you had them, as asked by itiwhetu? And what exactly is the "fertilizer" you are using? Light is another factor, especially since these plants are as far down in the tank as possible so light will be weaker. This light issue may not be the issue, the other two things are involved.

Click to expand...

I’ve had them for about a 2 months now. I’ve been using aquarium co-op fertilizer!

Navfish said:

I’ve had them for about a 2 months now. I’ve been using aquarium co-op fertilizer!

Click to expand...

So if I was you I would try keeping the lights on for longer. You may get more alage if you do this. Or maybe move the plant forward to see if other plants are blocking the light.

First my thoughts on the light...it is probably adequate in intensity and duration. These two aspects are not interchangeable, by which I mean that increasing duration does not benefit the plants if the intensity is not sufficient, and increasing the photoperiod (duration) is very likely to cause "problem" algae. I don't see algae issues now, so don't risk it. How long is the tank light on now? Just so we can get things in perspective.

The issue is likely the fertilizer. You need substrate tabs for Echinodorus plants, they are heavy root feeders, and while adding liquid fertilizer can benefit, you run a real risk of excess nutrients in the water which means...problem algae. This is not the case with quality substrate tabs. I use Seachem's Flourish Tabs and have for over a decade. One next to the plant's crown, replaced every 3 months. Here you could do two, place them in between the three plants. These really will make a difference.

As for liquid fertilizer, I've never used Aquarium Co-op but don't overdo it or you could again see algae issues. Especially since it contains nitrates and phosphorus which are known to cause algae in excess and are not needed here.

Not all plants require the same needs (just like fish, for that matter...). Nutrients, light, water hardness, etc could be in play. There are a serious number of plants that are sold as aquatic plants while they are swamp plants, garden plants or even a house plant. Those can bring some trouble along when kept in a fishtank.

I get the idea from various posts that people think plants should thrive just because they are plants. Simple life forms. In my experience plants are trickier than fish. A guy can watch a fish eat and swim and respond to water changes and different things fairly quickly , from a few minutes to a few days. Plants take time and they sit in one spot and you don't see what's going on right away. I had a plant that slowly fizzled out over six months and in that time I swore it was thriving but it is as dead as a door nail and gone forever now. Plants are tricky. Now I have two kinds that are doing fine and I am happy with that. There is also trimming to be considered but that's a whole other discussion.

There are 2 classes of nutrients plants need they are called mobile and immobile nutrients. And you might have a mobile nutrient deficiency.

Immobile nutrients are:Calcium, Sulfur, iron, Manganese, Zinc, Copper, and Boron.

mobile nutrients are Nitrogen, potassium, magnesium, phosphate, chlorine, Molybdenum and Nickel.

The Key difference in these nutrients is that plants can remove mobile from old leaves to support new growth. The old leaf then dies and falls off the plant.

Now plants get these nutrients from several places. Your water source, fish waste, fertilizer, and substrate. Substrate will have some nutrients when they are new abut they deplete over time. Your tank is likely old enough that your substrate has lost most of its nutrients. Fish waste does supply nutrients but you typically need a lot of fish. That leaves your water source and fertilizer.

Tap water almost always has enough Copper (from water pipes), Calcium, and chlorine (from the water sterilization process. So frequently these nutrients are not included in fertilizers. NIckel is also not included in most fertilizers simply because it was the last nutrient to be identified. fertilizer formulations had largly ben created by this pint. And most modern fertilizer simply copy old recipes. Also Nickel and molybdenum are only needed at a concentration of 0.000001 mg/L or 1 Part per Billion. Tap water likely has some so Nickel and and Molybdenum. so Mo and Ni deficiencies are seldom seen. Unfortunately tap water varies significantly from place to place and some people use RO water instead of tap or there tap water is RO water. So you cannot just assume the water has enough nutrients.

Your tank look quit good so I would recommend continuing with the easy green. I think the easiest thing to try is to also ad a mid week does of Seachem flourish trace a few days after the easy green dose. This would supply the copper and nickel that are not in easy green. The only other thing you can do is to test your nitrate level, you don't want to see zero. Yes you want to keep nitrate low as possible but zero is not good for plants. You can also test for GH and Phosphate. Phosphates are like nitrogen. keep it low but you don't want zero. GH test detects calcium and magneisum only. If the water is soft you might want to boost your water gh by just one degree with a commercial CH booster. That would satisfy the magnesium need. Also if the GH booster has potassium and calcium chlorine or magnesium chloride listed in the ingredients it will supply enough potassium, calcium, magnesium, chlorine. for nitrogen and phosphate deficiencies Seachem sells flourish nitrogen and flourish potassium. If you do all of that a mobile nutrient deficiency should be unlikely.

StevenF said:

There are 2 classes of nutrients plants need they are called mobile and immobile nutrients. And you might have a mobile nutrient deficiency.

Click to expand...

Just listen (read) to what he says. He knows what he is doing. Unlike me, I just dose API leafzone give them 12 hours if light and my plants bloom. I'm not an expert but I can give you good advice if you have a hobbyist meet up or something ask how keep there plants close to perfect and they normally have the answer. Don't just go to any LFS and ask go to a hobbyist meet up as I said before or a LFS with a lot of planted tanks for example maidenhead aquatics taunton (they have two heavenly planted tanks and a new blackwater tank if you want to see them YouTube MD fishtanks and should be one somewhere there) and just ask how they keep there plants and 99% of the time they will have the answers. Of course like the gentleman said mid week does of Seachem flourish trace try it and hopefully it will work. If not try root tabs to target the plant directly.

Back in the fold said:

I get the idea from various posts that people think plants should thrive just because they are plants. Simple life forms. In my experience plants are trickier than fish. A guy can watch a fish eat and swim and respond to water changes and different things fairly quickly , from a few minutes to a few days. Plants take time and they sit in one spot and you don't see what's going on right away. I had a plant that slowly fizzled out over six months and in that time I swore it was thriving but it is as dead as a door nail and gone forever now. Plants are tricky. Now I have two kinds that are doing fine and I am happy with that. There is also trimming to be considered but that's a whole other discussion.

Click to expand...

Yep, plants are harder than fish, in my experience too. They take a whole lot more patience. You make a change and then basically have to wait at least a few days if not a couple weeks before you know if it’s done anything.

Byron said:

First my thoughts on the light...it is probably adequate in intensity and duration. These two aspects are not interchangeable, by which I mean that increasing duration does not benefit the plants if the intensity is not sufficient, and increasing the photoperiod (duration) is very likely to cause "problem" algae. I don't see algae issues now, so don't risk it. How long is the tank light on now? Just so we can get things in perspective.

The issue is likely the fertilizer. You need substrate tabs for Echinodorus plants, they are heavy root feeders, and while adding liquid fertilizer can benefit, you run a real risk of excess nutrients in the water which means...problem algae. This is not the case with quality substrate tabs. I use Seachem's Flourish Tabs and have for over a decade. One next to the plant's crown, replaced every 3 months. Here you could do two, place them in between the three plants. These really will make a difference.

As for liquid fertilizer, I've never used Aquarium Co-op but don't overdo it or you could again see algae issues. Especially since it contains nitrates and phosphorus which are known to cause algae in excess and are not needed here.

Click to expand...

I have the lights set up to run from 8: 30 am to 8:30 pm. I will probably get the root tabs u said!