Plants getting yellow tops

[OnceLoyal]

This might be kind of a vague question, but a few of my amazons are turning yellow torwards the top of the leaves.
What is this normally a sign of?? Lack of nutrients? Lack of light? I will try and get some pics if you think it would help out a bit. They seem to be sprouting some new leaves still. ALso some of the other ones are beautiful and seem to have no flaws at all.

 

[frasertheking]

hmm well whats your set up ? tank, light, using co2 or dosing ? if i remember right this is an indicator of iron deficiency. just get a good liquid fert if its a small tank or consider dry ferts for a larger tank .

 

[WyldFya]

How long have they been submerged? Have they already gone through their emersed growth shed?

 

[OnceLoyal]

This is the 220 that I put a pic of up a little while ago. I don't think they ever "shed" so I am assuming or hopeing this is what is going on. They did go for awhile without any iron in the fert. I just started adding iron about 2 weeks ago. I am using a product or 2 products from Kent. One has no iron and the other does. I used some root tabs also. Maybe it is time to replace some root tabs als?
Thx for the quick replies.>

 

[WyldFya]

If they haven't lost their emersed growth, then it is likely this is all that is taking place. Post a pic.

 

[OnceLoyal]

Wyld I am having some issues for some reason getting the pics at a good quality. I will try again later this evening and try to post them them. Is it detrimental to trim the yellowing ones off? I will take pics before I trim though of course.

 

[WyldFya]

If it is shedding emersed leaves, then just leave them. If it is in its submerged growth already, then clip the leaves.