Glosso Deficiency Identification - Fertilizing

vim · 07-03-2009, 09:06 PM

Hi All.

The attached picture shows (sort of, sorry - web cam) glosso with both pale (browning) tips and holes in older leaves.
I tried dosing 3 days worth of macro nutrients all at once: it took abut 6 hours for the water to turn a lovely pastel green

Any thoughts on the problem would be much appreciated!

I'm currently dosing :

KNO3 - 2.45ppm/day
KH2PO4 - 0.47ppm/day
K2SO4 - 2.49ppm/day

Traces...

Thanks,
vim

Tex Gal · 07-03-2009, 09:15 PM

Looks like you need iron and maybe calcium.

vim · 07-03-2009, 10:36 PM

Other than adding more trace mix the only Fe I have available is FeEDTA 13.2%. I'll look into appropriate dosing information

Water here ranges from 3-5.5KH depending on rainfall. The less this changes in the tank the happier I'll be: here's hoping the plants don't need much.

Thanks for the quick response Tex Gal. I'll update with dosing and results.

vim · 07-30-2009, 08:29 PM

An additional 0.05ppm Fe per day and calcium (dolomite) resulted in much more tip growth, but it was pale and died very fast. This lasted about a week before tip growth slowed again.

I've recently added unmeasured amounts of K2SO4. This resulted in pearling about two hours after lights on so it might be a lack of K that's the problem.

experimentation continues X-)

green water ended up being an easy fix with 8 hours of UV.

Seattle_Aquarist · 07-31-2009, 07:40 AM

Hi vim,

It is hard to tell from the picture, but from what I can see it appears that the leaves have a "purple" tinge in the middle before the hole appears which could indicate a phosphorus deficiency.

The necrosis could also be caused by a magnesium deficiency, which I have here in Seattle due to our soft water. I dose with MgSO4 (Epsom Salts) per Rex Griggs' recommendation for my soft water and the plants respond fairly quickly.

Here is a link to a chart I use to diagnose problems (it may take a little time to load). http://www.finostrom.com.gr/images/a...lizers/map.htm

vim · 08-22-2009, 07:01 PM

Hi Roy,

I think you're spot on with the phosphorus deficiency.

Unfortunately additional PO4 accelerates growth quite rapidly and even new leaves on the Elodea are white.

Water here should contain 16ppm Ca and 6.5ppm Mg. Does this sound like enough?
1.2ppm Mg per day for a week produced no discernible change.

EDIT: oh. I'm seeing no drop in hardness between water changes. Would a lack of Ca/Mg show as a drop in General Hardness?

mrkookm · 08-23-2009, 09:44 AM

At .47ppm daily dose + whats in your tap as well as other other in tank contributors, I highly doubt what you're experiencing is caused by a PO4 deficiency. Give us more info on the tank specs (eg. lighting, lighting duration, Co2 rate 'if any'..etc)

What is your trace source and how much of it do you dose?

vim · 09-17-2009, 09:15 PM

Hi mrkookm,
thanks for the reply.

tank: 10usg (8 water + substrate etc)

substrate: local river sand and fine gravel.

lighting: cool daylight (6500K) CFL (link - not a lot of info)

lighting duration: 7 Hours @ 4.4wpg, 3 Hours @ 1.1wpg

reflector: diy. the above levels are just enough to keep glosso spreading rather than climbing.

Co2: yeast. 25-35ppm. measured by drop checker and calibrated by gasping fish (once

)

traces: garden variety trace mix (link - pdf). see 'code' for dose.

Code:

PPM / Week										
		NO3	PO4	K	Mg	Fe	S	Mo	B	Zn	Cu
KNO3		41.21		25.99							
KH2PO4			6.98	2.87							
MgSO4*7H2O				2.68						
Traces					1.00	0.50	1.70	0.0006	0.01	0.14	0.17
K2SO4				10.25							
50% water chng				3						
		41.21	6.98	39.11	6.68	0.50	1.70	0.0006	0.01	0.14	0.17

dosing: all dosed daily.

most recent changes to dosing:
added KH2PO4
-Elodea - very slow growth increased to about an inch a week

added K2SO4
-Elodea - growth increased to 4-6 inches a week. A little pale and transparent but not badly so.
-'hairgrass' - resumed growing runners, though very slow and pale.

glosso is almost gone now, so I'm on to saving the hairgrass

Zapins · 09-17-2009, 10:55 PM

Looks like N deficiency to me because the glosso leaves are getting smaller as they grow and the new growth is pale. But honestly, I think the best thing you can do is actually test the water with titration kits. Calculating what should be in the water is not the best way of doing things. Actual concentrations can be way off what is added.

Let us know the titration results, and try get more pics if you can.

vim · 10-12-2009, 06:59 PM

hi Zapins.

"titration" ?

I recently found and purchased Nitrate and Phosphate test kits, because fumbling around in the dark just isn't working.

First results were Nitrate: 30ppm, Phosphate 5ppm.

This was the day after a 50% water change ! so lead to a rather large "well duh" moment on my part: if you're dosing to keep up with uptake by healthy plants and they're _not_, you're going to end up with lots of unused fertiliser in the system.

The plan now is to check how fast Nitrates and Phosphates drop, then adjust dosing so suit.

Anubias barteri 'Coffeefolia' and Anubias barteri 'whatsit' have been in the tank for about a week. These were added in the hope of determining whether leaves are pale all over of just between the veins (no use looking for veins in hairgrass). Both are growing well but might be showing signs of interveinal chlorosis (or perhaps that's just how they look). If it gets worse my guess is iron deficiency due to excess K