Name that deficiency!

[majolo]

This is an Anubias nana leaf, one of the older leaves on the plant.

Tank info:
55gal
2x65W power compact 6700K, just put in new bulbs
photoperiod 12noon-10pm
Dosing:
SunTueThu:1/8 tsp Potassium Nitrate, 1/8 tsp Monopotassium Phosphate, 1/4 tsp Potassium Sulfate
MonWedFri:1/4 tsp Plantex CSM+B

Flourish Excel, 25ml Sunday (after 40%PWC), 5ml all other days.

No algae problems that I can see (I think that's a little bit of GSA on the Anubias, but that's about as bad as it gets). My Hygro salicifolia has also had the older leaves get yellow/white, but it grows fast enough that it's generally time to trim and replant anyways. But lately I've seen this in the Anubias as well, and would like to see if the experts can suggest any adjustment to my dosing.

(Before it comes up: I know someone will say I need CO2, but I (politely) decline. I've had the tank running on this regimen for over 6 months, no problems, and I don't think that's the problem with the Anubias. If someone feels strongly that I need less light, I've thought of trying cutting the light with a neutral density gel I got from a theater supply shop. It seems like that could be a nice way of fine-tuning light levels in planted tanks...)

 

[JDogg]

Potassium... i would double your Potassium Sufate Dose

just to check the amounts you gave are daily dosing amounts not WEEKLY totals right?

i would also double your Potasium Nitrate and only dose Phosphates 1 day a week at your current level

if you do not have the test kits i would pick them up to check current levels, but i am guessing you have a lot of phosphates and not a lot of Nitrates (in an ideal world you want to maintain 10-20 ppm NO3 and 1-2 ppm PO4)

 

[majolo]

Yes, the amounts given are daily (3 days a week for the macros and 3 days a week for the Plantex). My nitrates in the tank test at 10ppm pre-water change, so I think you are right on the KNO3. I have been tweaking that one, since at the original dose from some EI lite article I ended up with like 80ppm nitrate at one point.

I do have a Seachem phosphate test, so I'll check what that says too.

Thanks for the tips!

 

[Purrbox]

Looks like you're dosing:

0.33ppm Fe with the CSM+B
2ppm N with KNO3
2.25ppm P with the KH2PO4
4.25ppm K with the KNO3 and K2SO2

This confirms my suspicion that you're probably looking at Macro Deficiencies. I'd up the KNO3 by 3-5x and probably up the K2SO4 by 2x. You could easily drop back the frequency that you're dosing the CSM+B to once a week, or reduce the quantity to 1/2-1/3. Since you've got some GSA you may need more P as well, but I'd wait to see if upping the N helps before dosing more. If you're still seeing as much or more GSA after 2-3 weeks, I'd try bumping the KH2PO4 as well.

 

[majolo]

Hmm, I thought I replied a few days ago, but I must have forgotten to push Submit...

Anyway, those numbers are very helpful, Purrbox. Is there a calculator somewhere that does that?

I tested phosphates last week and they came out a bit off the top end of the scale, I'd guess maybe 3.5 ppm. So I doubt I need to increase them, maybe decrease a little bit? (I do know my tap water has some phosphates as well, about 1ppm last I checked.) I think I'll go with the following for now and see where my nitrates and phosphates are after a couple weeks:

Potassium nitrate: 1/3 tsp 3x a week
Monopotassium Phosphate: 1/8 tsp. 2x a week
Potassium Sulfate: 1/2 tsp 3x a week

Plantex: 1/8 tsp 3x a week

Is it still recommended to aim for a 10:1 nitratehosphate ratio?

 

[rkilling1]

Is it still recommended to aim for a 10:1 nitratehosphate ratio?

Some people shoot for that ratio, but it is not required. Just maintain your PO4's in the 1.0 to 2.0 range and your NO3's in the 10 - 30 range.

 

[Purrbox]

I highly recommend downloading Chuck's Calculator for determining dry fert dosages. You can visit czcz's page for the CSM+B calculations.

 

[czcz]

How old is it? Maybe it's emergent growth dying off. Lots of vendors grow Anubias emergent.

 

[majolo]

Well, I've had the Anubias since last November, and I'm pretty sure this was one of the original leaves.