Black patches on Java Ferns

[Karmicnull]

Hi. My 7 month old tank is largely in balance, and my Java ferns (Microsorum Pteropus Mini) have grown steadily after taking a few months to settle down, but with big black patches on the leaves. I haven't found anything hugely informative on the interweb. Any ideas?

1. Size of tank: 130L.

2. Filtration: Aquael Ultramax 1000 external

3. Lighting and duration. Nicrew lassicLED Plus running 2x3.5 Hr sessions at 70% with a 6 hour siesta in between and 5 mins sunrise/sunset either side.

4. Substrate: Thin layer of JBL aquabasis plus then Sand then light dusting of gravel

5. Co2 dosing or Non-dosing. No Co2. Low tech all the way

6. Fertilisers used + Ratios: 20% APF EI dosing +1ppm EDDHA FE. (hard water). Also 5mls of Glut (Excel) straight after WC, if you count that as a fert.

7. Water change regime and composition: 25% wc weekly - tap water. Tank kept at 22 degrees C.

8. Plant list. Alternanthera Rosaefolia; Anubias Nana Bonsai; Cryptocoryne crispatula; Cryptocoryne Wendtii Brown; Cryptocoryne Wendtii Tropica; Helanthium Bolivianum "Chain Sword"; Heteranthera zosterifolia (Star Grass); Hydrocotyle Tripartitia Japan (Three-part pennywort); Hygrophila Siamensis 53B; Microsorum Pteropus Mini (with big black patches); Microsorum Narrow Leaf (also patchy); Pistia stratiotes ("Dwarf Water Lettuce"); Pogostemon Helferi; Potamogeton Gayi (slender pondweed); Taxyphyllum Barbieri (Java Moss); Taxiphyllum Sp. 'Spiky Moss'; Vallisneria Gigantea; Vesicularia dubyana (Christmas Moss).

9. Inhabitants. Multitudes of CRS and tiny teeny ramshorns, 1 Zebra nerite, 2 red onion nerite, 4 x Amanos, 8 Cherry barbs 4 pearl Gourami, 7 Panda Corys, 1 Bristlenose plec.

10. Full tank shot. See below. Also a couple of the patchy Java Fern. The best info the interweb could give me was that this might be a CO2 deficiency, which could be challenging in a low energy setup!







It's not the only imperfection, but for all of the others I have a fair idea why the plants aren't as happy as they might be. All thoughts and suggestions welcome.

Cheers,

Simon

 

[PARAGUAY]

Its always a opinion of what you would do. If it was me l wouldnt have a lighting period like that. I know its a proven methodwith Dennerle though. You could reduce the lighting strength at least for now .Someone may advise about EI on low tech l prefer to use all in ones like Evolutions The Aquascaper or TNC on low energy tanks. So remove all worst leaves .Clean atround substrate level do water changes 25% daily for a week Check your floating plants for indication of defiecencys as Duckweed Index. Just what l would do for now

 

[Mark Nicholls]

I'm assuming that you DO have the plants attached to wood or rock as opposed to buried in the substrate.
IF your plants are attached to wood or rocks, that's OK.
If you only get the occasional leaf turning brown, its not a problem.
If you are getting lots of leaves turning brown all at once, its trouble.
Could be caused by rapid change of temperature or pH, excess lighting or damage from inhabitants.
Java fern is slow growing and therefore doesn't need co2. It DOES like lots of liquid ferts though. Heres our 20ltr aquarium which is medium lighting, ph 7.4 and dosed with ei ferts only.

 

[G H Nelson]

Your are actually using a Co2 in a Liquid form!
Use it as it describes on the bottle as per litres....up your fertilizer to full EI.
Direct flow down towards the base of the Java fern or move it nearer to where there is suffice flow around the fern......I would hard prune affected leaves....they are beyond saving!
hoggie

 

[Karmicnull]

If it was me l wouldnt have a lighting period like that... Check your floating plants for indication of defiecencys as Duckweed Index.

Java fern is slow growing and therefore doesn't need co2. It DOES like lots of liquid ferts though.

Your are actually using a Co2 in a Liquid form!
Use it as it describes on the bottle as per litres....up your fertilizer to full EI.

Thanks folks - Duckweed index is pretty happy. I did go too low for a while (went through an "I'm low tech - I'm kidding myself that I really need all this fert" phase) but realised the error of my ways. Then I had an Fe problem a while back which the index diagnosed for me, hence the EDDHA FE. I've been dosing Glut as an algaecide. Well, more accurately a way of making the environment less algae-friendly. Coupled with the Amanos it seems to have knocked Green Thread on the head. and the whole tanks seems indefinably 'happier' (including - bizarrely - the Vals). Through all this time the Java ferns (yes- attached to rock!) have been gently growing and throwing out babies that get caught up in moss exactly as nature intended, but in a black patchy way. I've never really bought the whole 'liquid carbon' thing. Seemed a bit like marketing to me, and opinion on the interweb is pretty mixed, with lots of anecdote but not great data. I can certainly try upping the dose slightly and seeing if that makes a difference - although I feel like that might be a slippery slope to the dark side. I'm also happy to try upping my ferts as well - it's fair to say my plant mass has increased considerably, so I might be undercooking it. Unless other voices chip in with alternative suggestions I can try both of those for a month or two and see if that makes a difference. I was also thinking about lighting. My other tank (also low energy) I'm trying long duration low intensity, as per @dw1305 and @Christel and it seems to be working, although it's early days. But I don't want to change too many variables at once.

Cheers,
Simon

 

[dw1305]

Hi all,

Through all this time the Java ferns (yes- attached to rock!) have been gently growing and throwing out babies that get caught up in moss exactly as nature intended, but in a black patchy way.

It <"might be the glutaraldehyde"> causing the black patches? They definitely look less healthy than they should be, but I've never had anything quite like that. We've had some threads where they've dried out during water changes, but that usually causes brown (not black) patches.

throwing out babies that get caught up in moss exactly as nature intended

Are all the leaves producing new plantlets?

cheers Darrel

 

[Hufsa]

I would try first just to sort out the flow to be honest, yours looks to be almost entirely behind the purple rock, and its not clear to me if there are any pumps or outlets that are pushing flow to that area.
I put my Windeløw in a low flow corner of the tank and in less than a week it started getting black spotted leaves like this and looked unhappy.
Make sure yours gets enough light as well, trim floaters if you need to to achieve this.

If flow doesnt fix it next I would bump up the ferts just a smidge.

I think its unlikely that the light period is killing just one plant in an entire tank. And as youve said its given you good results overall so far.

All plants need CO2, they just need them in different amounts and it depends on the light as well.
Glutaraldehyde adds maybe 3 ppm of CO2, I think ive read, its primary function is as an algaecide. +3 ppm of CO2 doesnt make it a high tech tank that needs full EI, but thats just my opinion.

Trim the worst leaves, if they are all bad leave the youngest ones behind in a decent amount so that the plant can still photosynthesize. Java ferns take forever to get rid of old leaves on their own. This will also improve flow through the plant.

 

[John q]

<"might be the glutaraldehyde"> causing the black patches?

Had this but worse on a java fern that was dosed with excel, from the rhizome all the way up the leaf, ended up binning most of it.
It was sat up on log and basically in the area I used to dose the glut.

 

[G H Nelson]

Java sp need a lot of flow to bring out the best in them!

 

[Karmicnull]

It <"might be the glutaraldehyde">

Had this but worse on a java fern that was dosed with excel,

I don't think this is glut related as it pre-dates my use of Excel.

Are all the leaves producing new plantlets?

I have absolutely no idea. This arrived at the top of my list at last weekend's WC when I realised I didn't have anything else to fret about. So I'm only now starting to pay it serious attention!

sort out the flow

Java sp need a lot of flow

OK this may have legs. There is flow around the ferns, but it's very gentle - they are quite near the filter intake, which I had imagined would be a high flow area, but nuances of topography appear to have prevented that. Also this is a fabulous excuse to invest in a powerhead, and I've been wanting to do that since I first read about them 7 months ago (even though at that point I had no idea what they were, apart from the fact that they sounded cool).

 

[dw1305]

Hi all,

I have absolutely no idea. This arrived at the top of my list at last weekend's WC when I realised I didn't have anything else to fret about. So I'm only now starting to pay it serious attention!

I do that as well.

Usually lot of new plantlets are produced on old fronds before they senesce, or when the plant isn't very happy.

cheers Darrel

 

[Mr.Shenanagins]

Pretty sure black spots is a CO2 issue. I’ve only noticed this in my low energy scapes.

 

[Karmicnull]

Usually lot of new plantlets are produced on old fronds before they senesce, or when the plant isn't very happy.

I wondered about that. I am now monitoring!

Pretty sure black spots is a CO2 issue. I’ve only noticed this in my low energy scapes.

All the references to similar issues I could find both here in UKAPS and elsewhere said 'dial up the CO2'. I remain optimistic that there's a low CO2 sweet spot to be found. Otherwise I'm sure there would be a lot more "low CO2, unhappy java fern" posts littering the internet. I've set @Mark Nicholls photo above as my aspirational target!

 

[ceg4048]

All the references to similar issues I could find both here in UKAPS and elsewhere said 'dial up the CO2'. I remain optimistic that there's a low CO2 sweet spot to be found.

Yes, and these are correct. One cannot have a low CO2 sweet spot when the lighting is too high. High light forces a high CO2 demand.

Otherwise I'm sure there would be a lot more "low CO2, unhappy java fern" posts littering the internet.

There ARE a whole lot of low CO2, unhappy java fern posts The answer is always the same increase effectiveness of CO2 and/or reduce the lighting load.

Cheers,

 

[Karmicnull]

The answer is always the same increase effectiveness of CO2 and/or reduce the lighting load.

I did a small amount of research on my lighting. Values below at 70% intensity, which is what I'm currently running at (substrate is 48 cm from the light).

[EDIT: pasted the wrong table in last night - have updated with the correct one ]
Given that the light is obscured by a layer of Pistia stratiotes, the Java fern is towards the end of the tank, around 10cm raised from the substrate and the light is 75 cm long rather than the full 92cm of the tank, I reckon that it's getting at most 40 PAR and probably a fair bit less. Would you consider that to be high light? I'd thought it was about target for low energy, but I'm happy to be corrected.
On a related note I did a little bit of analysis of my success/failure with plants to-date <here> and concluded that the biggest correlation I had was with lighting (plants I bought with high lighting requirements were 3x more likely to die than ones with low lighting requirements), with the second biggest being CO2. Again that led me to conclude I didn't have high lighting.


Cheers,
Simon

 

[Mr.Shenanagins]

I think anything over 30 par is considered in the medium light range

 

[Karmicnull]

I think anything over 30 par is considered in the medium light range

I feel a need to challenge my assumptions! I went to my notes to see what they are based on and BAM! I'm on the naughty step: no references😡. My PhD supervisor would be turning in his grave, only he isn't dead, so he can't. In penance, I've done a quick literature search:
<The planted tank> says 10-30 is low light, 30-80 is medium, and 80-120 is high.
<Aquariumpardata.com> says 15-30 is low light, 35-50 is medium and >50 is high
<The Two Hour Aquarist> has a really interesting article with a number of juicy data points, and says "The main downside of using higher lighting is that one may face more algae issues. I use 100 Umols of PAR effectively in my low tech tank setups, but for those looking to growth[sic] plants not usually suitable for low tech tanks, I would recommend a range between 60-80 Umols at substrate level."
<Fishlore.com> has a long article about low light tanks without specifying what low light is. My supervisor has failed them. Although they do reference <another article>in the planted tank which cites the same numbers as the aquariumpardata article.
<PortlandAquarium.net> says 15-30 is low light, 35-65 is medium, and 65-120 is high

So It looks like there is scope for reduction. Although as always it's a juggling act - the Pogostomon is a happy camper and there are a pile of plants on the RHS side of the tank that are already not really growing due to shading and being off-beam. Reckon I'll have to use my new-found understanding to rethink some plant locations. In the meantime I'll maybe try dropping to 65%


Cheers,
Simon
P.S. I'm still going to try a powerhead, because, well, powerheads!

 

[Tom101]

@Karmicnull if it helps at all, I've had the same issue with my Java Fern in a high light, low co2 set up. I've drastically reduced my photo period and intensity (and pruned) - now I'm getting new growth.

More food for thought - I'd noticed that some leaves had been covered in green spot algae too, which I assume had worsened the issue.

 

[Karmicnull]

@Karmicnull if it helps at all, I've had the same issue with my Java Fern in a high light, low co2 set up.

Yes it definitely helps! More data points = better science!

 

[Tom101]

Yes it definitely helps! More data points = better science!

Brill - extra info below. The light is a 500mm Fluvial Plant 3.0 using it's full spectrum.

Original exposure
- 8hrs at 60% intensity

New exposure
- 5hrs at 40% intensity