Plants not doing well...help

[Enchantress]

Hi,
The plants in both my 45l and 30l tanks are not doing too well, and I'm not sure why. I've spen hours online trying to ID the problem, without much success tbh. In the bigger tank I have a LED light that gives out about 21 lumens/litre, and in the smaller one I have 2 old 7W LED lamps. I dose both aquariums with liquid carbon, micronutrients and macros (special formula for slow-growing, low-light plants). My Indian fern's leaves are dissolving in places, with irregular holes and brown patches, the Java ferns have developed brown/black tips and spots on the leaves, which tend to die off (they are NOT spores), and the leaves on my anubias are curling and bending backwards. In spite of this, all the plants are regularly sprouting new shoots and leaves (except for the Windelov ferns, which seem to be struggling). Both tanks are heavily planted and understocked (1 fish in each, plus some shrimp and snails). There are both fast- and slow-growing plants in there, which is why I'm also concerned about dosing this macronutrient mix for slow-growers, since I'm not sure the other plants are able to use it efficiently...or does it not matter? I'm not sure what they could be missing - macros, or maybe potassium, iron, magnesium or calcium? Should I stop the ferts for the time being and see how they do, or should I try adding something - if so, what? Thanks in advance for any help, I'm scared I'm going to lose these plants...

 

[SaraB]

You don't need carbon in your tank all the time. How long are your lights on?

 

[Enchantress]

You don't need carbon in your tank all the time. How long are your lights on?

Good to know. I'm running out anyway, so maybe I'll hold off on getting more and see how they do without it. My photoperiod is usually about 9 hours. Also, if it helps - I noticed that some of the young Java fern leaves (not the Windelov, the regular big ones - I have 2 varieties) are a bit pale, especially in comparison with the older leaves...they're not yellow, they just look pale and washed-out. I've come across a set of liquid ferts that consists of macros, micros, potassium and iron (all in separate bottles) and I'm thinking of maybe switching over to it. It would work out cheaper and more efficient than the ones I currently have. Do you reckon it would be a good idea to start using them?

 

[Enchantress]

Also, most of the leaves are curling backwards and sideways. Esthetically speaking it doesn't bother me, I'm just worried that it'll progress and they'll start dying. The leaves on the Indian fern keep getting these weird translucent patches that then progress to irregular holes and decay. It's be a shame if something happened to it, it's such a big and beautiful fern, takes up half the space in the tank If anyone has any ideas as to what the plants may be missing, I'd certainly appreciate any help or advice you throw at me

 

[Dougthecat69]

The snails love to eat the plants, I have dealt with the same and those where the issue for mine. Could also be black allege which a co2 booster along with light could be causing have you tried lead zone.

 

[Enchantress]

The snails love to eat the plants, I have dealt with the same and those where the issue for mine. Could also be black allege which a co2 booster along with light could be causing have you tried lead zone.

I don't think the snails would cause such widespread damage...I just have some ramshorns and bladder snails, and not in particularly high numbers. Most are very small. I'm pretty sure it's a nutrient deficiency of some kind. I've considered algae, but whatever is on the leaves doesn't come off when I rub them, it looks more as though the blade itself has changed colour. Te Windelov fern looks "burnt" at the edges. And the Indian fern is looking worse every day, some of its leaves have now dissolved to the point where only the veins remain

 

[Enchantress]

This is what the situation is like today. As you can see, the Indian fern is still dissolving and some of the leaves are curling and twisting badly, the Windelov leaves are getting black patches that turn into decay (some tips have receded completely, leaving only the main vein in the middle - unless of course this was done by the snails), and the hornwort, which for the most part is doing very well, occassionally sprouts thin, pale needles instead of the normal thick green ones. The tanks still look OK, but the decay is definitely visible, even to the "untrained" eye. I'm sure there is some kind of nutrient imbalance that's affecting them, but I'm not sure how to correct it, or what it exactly is. The tanks are understocked and I never overfeed the animals, but there is quite a lot of decaying plant matter in them, so the plants should be getting the macros they need from that, right? Although there's a lot of them crammed into fairly small tanks, and many are fast-growing nitrate guzzlers like hornwort, wisteria and frogbit...maybe that's the problem? In that case, would it be OK to dose the water column with, for example, a mix of macros/micros/potassium/iron, even in a setup that's low-tech & no CO2?