[Zapins]

Rush3737- I somehow missed this post for the last 2 weeks.

This is almost certainly potassium deficiency. It looks a little weird in lotus plants due to the huge holes it makes rather than the pinholes we are used to seeing. Just double check that the holes are forming on older lotus leaves (looks like they are to me but I don't have the plant in front of me to double check!).

Adding K2SO4 is a very good idea and will likely stop further plant degradation.

Do you think you can get some close up photos of each of the affected plants in your tank? I'd love to be able to add more photos to the DeficiencyFinder (without lighting glare on the water surface). Photos of old leaves in particular would be helpful, and new leaves if there is stunting with them.

Here is an entry I just recently added to the Deficiency Finder that you should read:

http://deficiencyfinder.com/?page_id=789

 

[Zapins]

Yep, looks like potassium deficiency. The Rotala holes are typical of potassium deficiency. As a side note, even though the ferns had the holes from before you got them, they are pretty bad indicator plants in general. The old leaves always seem to look ratty which makes them look deficient even when they are not.

As for the high K usage, I know what you mean. It is odd but it seems some tanks require more potassium than any other nutrient. My 90g tank consistently uses more potassium than nitrogen. I've even had my water professionally analyzed to be sure it is a lack of potassium. I think certain plant species just take up more potassium than others. My tank is mainly java fern/anubias and rotalas, so perhaps one or all of these plants have a very high potassium uptake requirement?

 

[Zapins]

What ferts are you currently adding (in the last week)? Are these plants all in the same tank as the original plant photos you posted? Can you test the water parameters (NO3/PO4/GH/KH)?

Collectively these symptoms are looking a bit strange. Have the holes stopped appearing on old leaves? It is possible that you were low on two nutrients, potassium and something else (possibly iron or nitrogen) then once you replaced the potassium the plants ran out of the other nutrient. This way the plant has not had enough time to grow enough healthy growth to easily distinguish the two since both the potassium and the new deficiency signs are on the same plant within a few leaves of each other.

The pearling isn't an indicator of growth it just shows oxygen saturation in the water. If your plants are deficient or in a toxic environment they will produce less O2 and less pearling.

 

[Zapins]

In the last week I've been doing .75tsp of K2SO4, .25tsp KNO3, and .18tsp KH2PO4 for macros, and my usual .25tsp CSM+B and a tad of extra iron for micros. I haven't checked parameters in the last two days, but I will again tonight for you.

Is this a daily dose or weekly in your 75g tank?

Also, you should consider buying a digital jeweler's scale on ebay instead of using teaspoons. Grams are much more accurate to use when dosing and the scales are very cheap, only $15 or so.

 

[Zapins]

Looks fine, 0.1 or 0.01 grams is acceptable for dosing ferts.

 

[Zapins]

Hmm. This is looking less like a deficiency and more like a toxicity of some kind. It appears you have enough N, P, K, Ca, Mg, and micros and yet your plants are still deformed and damaged.

Do you have access to RO water? Perhaps a few large water changes to flush out whatever you currently have in the tank and start dosing again using your accurate digital scale will solve this problem. I think that is your best option at this point.

I'd hold off on dips for the moment, you don't want to complicate the issue with potentially harmful dips if possible. I'd say first figure out the plant growth issue then the algae issue can come next. If you do too much at once you won't know what caused what.

 

[Zapins]

Plants all have different tolerances to nutrients and harmful compounds so it is expected that some would be affected and others not if it was a toxicity issue that is mildly harmful. Try do a few large water changes back to back to reset everything with your tap water then try dosing using the digital scale. If that doesn't work there aren't too many options left without using RO water and reconstituting.