Is my Alernanthera dying?

[Koenator]

I am not sure, but it seems like the leaves are yellowing a bit since I received the plants in the mail. If so how do I stop them from dying?

EDIT: The undersides of all leaves are bright red, it’s just the tops that are yellowish.

 

[Colin_T]

If the leaves have been damaged there is nothing you can do to help them. The plant will shed them if they are no longer useful.

Give the plant good light and a bit of aquarium fertiliser and see how they do.

 

[Stan510]

I think a few days with bright lighting will help it recover from being shipped. Looks fine overall. You could hit it with a shot of iron,that's always a good thing for plants.

 

[StevenF]

Your plants are loosing the lower leaves. only the top of the stem is growing. This is a classic sign of a mobil nutrient deficiency. Yours plants are removing nutrients from old leaves to support the growth of new leaves. The old damaged leaves then fall off the plant. Mobil nutrients are Nitrogen, Potassium, magnesium phosphate, chlorine, Molybdenum, and nickel.

Molybdenum and nickel are only needed at 1 part per billion. It is likely that tap water has enough of these 2 nutrients. Chlorine is used to sterilize water and it likely present in your tap water. Note water conditioners don't remove Chlorine They simply lock it up a a safe salt which plants can use.

First thing I would do is to check your ammonia, nitrite, and nitrate levels. If all are zero you could be short on nitrogen. Dosing a small amount of nitrogen would help. You could by Seachen nitrogen and follow the directions to dose to 5 PPM (a safe level). You could also get a phosphate test kit. If that is low you can use Seachem phosphate to dose to 1 PPM. If nitrogen and phosphate are fine you can add a small amount of Epsom salt (Magnesium sulfate) can be added. 5 PPM of magnesium is a good level or you can buy a GH booster and use it to increase your water hardness (GH)by one 1 degree. GH boosters also contain Calcium which plants also need. If all of that is OK you likely have a potassium deficiency.

Many general purpose fertilizers have Nitrogen, potassium, Magnesium, and phosphate but some don't contain nitrogen and phosphate. Check the label carefully

 

[Wills]

If its just been added to the tank and growing better from the tips is that not just it transitioning from emerged to submerged growth? These plants only go super red under high light (with Co2) so in regular lighting I think this is correct green/yellow on top and red/pink underneath.

You could snip off the sections with the leaves and replant them without the stalks at the bottom and as suggested feed them with some ferts and I think you can see some improvements.

Only other thing to mention is I think Alernantheras do best in soft water, so I've never been able to grow it in my hardwater for example - I've only ever tried the mini species but it just melts away on me.

Wills

 

[Colin_T]

There's also a pink Alternanthera and it resembles the plant in the picture. It has shorter leaves and paler leaves than red Alternanthera.