Hi all!

My setup for my 100cm tank. I would say roughly 50G of water column and 6 months old.

26~27 deg

4x39W 3' T5HO for 6 months ( just changed to 2 x 150W 8000K HQI) 8 hours daily

CO2 1~2bps 24/7

1/2 tsp Potassium sulphate, 1/8 Potassium nitrate, pinch of phosphate, 3 caps of seachem trace and 1 capf seachem FE three times each week.

40% water change every Sunday with only 1tsp seachem equilibrium added.

Heavily and densely planted with Hemianthus micranthemoides, Elatine triandra, Rotala wallichii, Ludwigia brevipes, Riccia fluitans, Riccia sp. dwarf, Cryptocoryne wendtii, Rotala sp. green, Rotala indica, Hydrocotyle sibthorpioides, Bolbitis heudelotii, Eleocharis acicularis, and Microsorum pteropus narrow.

20ish yamatos, 30 cherries, 5 otos, 3 saes, 30 galaxy rasbora, 30 green neon tetra and 4 marble hatchet. Feeding is micro pellets once a day.

My tank is doing great! but there's one small problem. my Hemianthus micranthemoides, which occupies the bulk of my aquascape, is suffering from minor dead shoot tips. This plant is actually doing great with healthy stems and big green healthy leaves even the shoots, but somehow about maybe 10% of them with healthy tips will suddenly starts to melt away. I'm not quite sure what is the problem, but am I right to say that it is suffering from either trace or calcium deficiency? This is the only problem for my tank and it only appears on my Hemianthus micranthemoides.

What do you guys think?
Many thanks in advance.

Test the phosphate level and see what it's averaging. Feeble or distorted new growth tends to come down to Po4. HTH. Prof M

Was that an Imperial pinch or SAE ?

HM is a weed, it sucks out a lot of NO3 and the genus does well/better in richer water column ferts. This is very true for Mic umbrosum and this species.

If not NO3, then CO2.
You are not adding much KNO3, about 1/2 what many may add for this tank size.
You have a lot of light for this tank, 4x39w T5's.......that is a lot of light.

So high CO2 and NO3 demands. Even with ADA As etc, you'll still need more KNO3.
Many folks trying to run leaner systems often have this same trouble, especially if they slack off a little on the dosing routine, that's the risk you take with low steady concentration rates etc.

Add more, it does no harm, also, switch to adding CO2 in the day only.
You can add more with less fish stress and more for the plants.


Regards,
Tom Barr

It is somewhere in between imperial and SAE, so I guess it should be ImpeSAE? ;p

Anyhow I could use more phosphate for sure, but I always thought phosphate deficiency always starts from the older leaves first?

Yeah HM is definitely a weed! But I love this delicate weed

But isn't nitrate and phosphate deficiencies only surface on older leaves first?

But anyhow I will try increasing both nitrate and phosphate and monitor the situation, and will update you guys.


Many thanks!

The thing that I don't understand is why only my HM is showing this deficiency when the the rest of my flora in my tank is very healthy even though they are fast growers stem plants too?

Hey there,

I've had exactly the same problem in my highlight (4 w/gallon T8 11 hours/day) 30 gallon tank about a month ago. All my plants were thriving, except HM and Mayaca. A small percentage of stems will either grow stunted or rot away. I eventually solved it by doubling the recommended nitrate and phosphate dosage, from 1/4tsp KNO3 and 1/8tsp KH2PO4, to 1/2tsp KNO3 and 1/4tsp KH2PO4. However, my fish didnt respond well to the change, so I've decided to drop the dosage back to the recommended levels, and reducing my photo period to about 9 hours/day.

So I would agree with Tom and try increasing your KNO3 levels.

Hope this helps.

Regards,
Steve

In your own words you say that the HM makes up the bulk of your scape. Would you say it also exhibits the highest growth rate as well ?

The draw back to high light sytems is that in extreme cases we may very well define the limiting factor often Co2, or nutrient deficiency.

Plants are highly adaptive in contrast to other life forms and readily cope with their enviornment. what I mean to say is that just because they can does not neccessarily mean they should.

Generally speaking, the perk of EI is that nutrient potential is unlimited... "Within Reason"

Excessive lighting commonly throws everything out of kilter. 2.5 - 2.75 wpg. is plenty of light. Growth is more commonly limited by insufficient Co2 and no amount of light can alleviate that.

I would scale back the lighting first, observe and then perhaps readdress nutrient defficiency, but only one at a time to allow you to witness individual results.

I often refer to highlight deficiencies as "Shooting Star" syndrome. "The candle that burns the brightest, Burns out the quickest" ! Generally by establishing it's first deficiency, but even the finest livestock requires sufficient rest, and prudent handling.

My wife recently cut her lighting to half the original wattage, and doubled the growth rate in her tank. Gorgeous thick green growth too. Go Figger ?

F.T.R. that tank is a 50g. W/ 4-36w CF @ 6700k on a split 10/5 hour cycle...So your original lighting looks pretty good to me.

Thanks guys for your pointers!

My HM takes up about 30% of my tank, which is about the same amount as my Elatine triandra. My HM does shows healthly and lush growth, but its growth rate is nothing compares to my Elatine triandra, Rotala wallichii, Ludwigia brevipes, Riccia fluitans, Rotala sp. green and Rotala indica. In fact all the plants in my scape are exhibiting healthy growth with zero signs of any nutrient deficiency, except for a small percentage of my HM.

Let me give a better explaination of the symptons on my HM. It happens only to a small percentage of my HM, and only on the top 2" of the plant . The leaves that are affected are actually well developed and not just the shoots at the tip. It seems that before it melts away, the color on the center tissue of the leaves are very light green in color. The stems on the top 2" of the plant are also affected as well.

My old lighting setup is decent, but aparently not enough to supply light to the both ends of my tank, which results in very very slow growth to my plants in those places. And those plants happen to be high light requirement plants. In fact my new HQI setup is giving all my plants even healthier growth than before. Not only they are showing more vigour and lush, they are also becoming more compact. Where else they are more leggy under my old lighting setup. The only setup back is more heat coming from my chiller with more frequent kick-in.

For now I'm doubling my phosphate in each dosage, and instead of dosing everything 3 times a week, I increased to 6 times a week.

Will update you guys later. Many thanks again!

I can tell you, you may have some species, such as the fast aggressive growers do well, while another species wanes.

Generally I think it's CO2 related, it's the lion's share of the nutrients planmts compete with eachother for.


Light is the other. From the sounds of it, you have lots of stem plants and likely need to prune often, shading causes leggy growth, not so much intensity of the light unless it's pretty low.

But that will not cause stunting/melted tips either..............

No excess nutrient application will either.
However, too low most certainly will.

As the tank changes through time, does the biomass with all these stems plants
remain the same?


No.


So do you think the nutrient levels also stay the same?
How about the uptake rates?

Do you think 5 cats eats the same rate as 20 cats to maintain the same growth?

No.
Same here.

I see this all the time in marine refugiums where the owner says they have great growth for several weeks, then as the biomass is now huge, the plants all melt.

Basically it ran out of food and exceed the supply from the tank.

Do you think that some plant species might have higher or lower demands for nutrients? CO2?

Certainly.
I've seen Myriophyllum beat up on Rotala when the CO2 was too low, light was high, nutrients where high.

Adding more CO2 solved the Rotala issue pretty quick.


Regards,
Tom Barr