# Long Term Filamentous Diatoms



## cbaum86 (25 Jun 2020)

I seem to be having issues with, as the title eludes, long term filamentous diatoms. Or at least that's what I believe they are.

From my research here and other sources the general consensus is this will burn itself out. Whilst that was the case with the dust type diatoms, I've not seen them for a couple of weeks now this stringy stuff just isn't backing off; if anything getting worse. They started to appear coming up to 4 weeks ago now, just on a few plants at first, they now cover most of the plants.

As you can see from the photos below it is quite bad, this is around 3-4 days growth.

*Aquarium details
AS900*: 186 litres.
*Planted*: 28 April - 2 months old.
*Light*: Chihiros RGB Vivid - 70% from 15:00 to 20:30 with 30min ramp either side.
*CO2*: From 13:00 to 19:30 - Light green drop checker / ~1.0 pH drop by 14:30 (light ramp start).
*Ferts*: 15ml TNC Complete daily, dosed at 13:00.
*Substrate*: Tropica Soil and Unipac sand path
*Water Change*: 60% twice a week.

I'm currently removing as much of the filaments with a brush and syphon from the plants each water change. I obviously don't get them all but I'd say at least 75, maybe 90%.

So a few questions:

Is it 'normal' for this to last as long as it is, coming up to a month and seemingly only getting worse?
Do I continue as is, removing as much as possible each water change?
Should I up water changes?
Should I stop trimming back plants (mainly rotala each week) to leave as much mass as possible?
Do I just need to wait it out - how long before determining it's not just going to burn itself out?
Is it possible to be something in the water source?
Is it likely to be an inbalance (lights : ferts : co2) and if so what should be the first change?









I'm not sure more details are needed but here is the journal to date (or 2 weeks ago).

Thanks and appreciate any help, getting a little frustrating and depressing.
Chris


----------



## Geoffrey Rea (25 Jun 2020)

cbaum86 said:


> *Water Change*: 60% twice a week.



What time do you do your waterchanges? Before co2 on, during the photo period or after lights off?




cbaum86 said:


> Should I stop trimming back plants (mainly rotala each week) to leave as much mass as possible?



Are you trimming plants back and discarding the tops... or replanting tops of stems?


----------



## dw1305 (25 Jun 2020)

Hi all, 





cbaum86 said:


> long term filamentous diatoms. Or at least that's what I believe they are.


They are, the're "Synedra" or _Fragilaria. _It may sound a  bit of a strange question but how much , and what type, of filter media do you have ?

Have a look at <"NACD Nature ......"> and <"The Celestial Swamp.....">.

cheers Darrel


----------



## cbaum86 (25 Jun 2020)

Geoffrey Rea said:


> What time do you do your waterchanges? Before co2 on, during the photo period or after lights off?


Water change in the morning before co2 on. I put the lights on around 5% when doing this so I can see what I'm doing but they go off again whilst its filling up. So depending on the depth of maintenance they could be on for an additional 20 - 60mins.



Geoffrey Rea said:


> Are you trimming plants back and discarding the tops... or replanting tops of stems?


I was replanting the tops but the past 2 trims I have just discarded as I trimmed pre algae removal and didn't want to replant tops covered in the stuff.


----------



## cbaum86 (25 Jun 2020)

dw1305 said:


> They are, the're "Synedra" or _Fragilaria. _It may sound a bit of a strange question but how much , and what type, of filter media do you ?


It's an oase biomaster 600 so I have the pre-filter sponges, then bottom to top is blue (20ppi) sponge, 2 trays of generic ceramic rings that came with an old APS filter, 1 tray of Seachem matrix and top tray is a thin orange (30 ppi) sponge.

I rinse out the prefilter each water change but I haven't looked inside the main filter yet.


----------



## dw1305 (25 Jun 2020)

Hi all, 





cbaum86 said:


> It's an oase biomaster 600 so I have the pre-filter sponges, then bottom to top is blue (20ppi) sponge, 2 trays of generic ceramic rings that came with an old APS filter, 1 tray of Seachem matrix and top tray is a thin orange (30 ppi) sponge.


I might be tempted to take a look in the filter body.  How dirty has the pre-filter been?

I'm not a fan off anything that impedes flow too much in the filter. We have  a couple of Oase filter media threads, <"Biomaster 250...."> and <"OASE 250 thermo ...">.

cheers Darrel


----------



## cbaum86 (25 Jun 2020)

dw1305 said:


> I might be tempted to take a look in the filter body. How dirty has the pre-filter been?


I'll take a look inside the main body tomorrow but the pre-filter has been surprisingly clean. Small patches of brown and squeezing there is barely any noticeable tinge to the water.

I purposely left the baskets with bio media fairly sparsely populated but I could look at changing the sponges for more coarse ones. I'll check out those threads.

Cheers.


----------



## dw1305 (25 Jun 2020)

Hi all,





cbaum86 said:


> the pre-filter has been surprisingly clean. Small patches of brown and squeezing there is barely any noticeable tinge to the water.[ I purposely left the baskets with bio media fairly sparsely populated


No that sounds fine. I'd probably just carry on with manual removal and hopefully eventually it will go away.

cheers Darrel


----------



## Geoffrey Rea (25 Jun 2020)

Darrel has pointed to throughput through your filter.

You’re not running a skimmer and doing two water changes per week. Is there any surface film buildup? Is this the reason for two weekly water changes? Is gas exchange being impeded is what I’m getting at.




cbaum86 said:


> Water change in the morning before co2 on. I put the lights on around 5% when doing this so I can see what I'm doing but they go off again whilst its filling up. So depending on the depth of maintenance they could be on for an additional 20 - 60mins.



No problem there then. Thought your Co2 may be getting fluctuated, putting your plants on the back foot whilst diatoms proliferate.




cbaum86 said:


> I was replanting the tops but the past 2 trims I have just discarded as I trimmed pre algae removal and didn't want to replant tops covered in the stuff.



Having never had Synedra was looking at your photos in your journal to see how it behaves. Other tanks that have suffered with general diatoms have got clear with time once a system matured from experience. However, this presumed the system is being run optimally for plant growth and nothing is being done to additionally stress plants. I’m basically fishing for improvements on your system, as attempting to inhibit diatoms comes at cost to your plants. The one thing I know of that will stall the maturation of a setup is inadequate O2.

On the more practical side you could try lifting your lily pipe at night to get high surface agitation/gas exchange:


----------



## cbaum86 (25 Jun 2020)

Geoffrey Rea said:


> You’re not running a skimmer and doing two water changes per week. Is there any surface film buildup? Is this the reason for two weekly water changes? Is gas exchange being impeded is what I’m getting at.


I actually bought a skimmer a couple of days ago in an un-educated attempt to help, just waiting for it to arrive. There is no surface film build up and I have a gentle ripple across the surface currently so I don't _THINK_ I have a problem there but I don't _KNOW_. The only reason for the two weekly water changes was a maintenance session to remove the filament buildup.



Geoffrey Rea said:


> I’m basically fishing for improvements on your system


I was hoping someone would say, "hey numskull you're obviously doing this wrong". Most posts I've found on the subject seem to say it will go with time but don't specify how long. The only one I saw with a timescale was on here which said it all but disappeared after just over a week - I can't find the post now. This has got me thinking that me seeing it over several weeks means I'm doing something wrong.



Geoffrey Rea said:


> On the more practical side you could try lifting your lily pipe at night to get high surface agitation/gas exchange:


I'll try doing this for the next week or 2 and see if it improves things.

Thanks for the help.


----------



## Geoffrey Rea (25 Jun 2020)

Just avoid getting disparaged @cbaum86

Diatoms in general can look horrendous but if you look at your plants they look healthy.

Haven’t the breadth of knowledge of @dw1305 on particular species so hesitant to treat all types as the same imposter. Also treading carefully as don’t want to put out a bunch of old wives tales.

If it were my own tank here’s what I would do and in order:

- increase o2 availability at night. If your plants aren’t photosynthesising as efficiently in the photo period, then running a continual input (like raising the lily pipe) *at night* from surface agitation at least ensures they’re taken care of during the hours of darkness. Gas exchange vs biological means of o2 production.

- second up is asking someone to donate some soil or media from a mature tank and put it in *after *supplying a consistent input of o2 at night through gas exchange. The theory being is the existing bacteria/archaea in that media/soil may become dominant and o2 won’t be as limited to help them along.

- third, and perhaps most important, is leave your settings alone unless you have good reason to do otherwise. Lost count of the customers who I’ve come across who start randomly assigning light intensities and twisting that Co2 needle valve to only create more problems. If the plants are currently growing and healthy they are your primary customers.

The main tank that this reminds me of is George Farmer’s iwagumi at AG that was diatom city at startup. We stayed the course with that one. The only bit that differed was I brought some yellow shrimp in and @Siege poured the lot in, water, shrimp and debris - tank cleared up. I’m sure he’ll give you his thoughts if I’ve missed anything.

PS love your Iwagumi rock arrangement. Really nice work.


----------



## cbaum86 (25 Jun 2020)

Thank you again @Geoffrey Rea, appreciate it.

I'll try as you say and certainly avoid tinkering.
The plants are fairly healthy underneath, I just need to keep on top of manual removal so they're not smothered with an impact on photosynthesis.

Haha, chin up. Unless this lasts another 4 weeks and then I may look for a hammer!


----------



## alto (25 Jun 2020)

I’d go with daily removal and water changes (as always assuming you’re free of the bucket brigade - or you love the daily workout )

As shown above, lifting the lily at night is always good


----------



## Geoffrey Rea (25 Jun 2020)

alto said:


> As shown above, lifting the lily at night is always good



Have actually found a caveat to this @alto

Borrowed a dissolved o2 meter from a friend at uni and found that on a mature high tech setup I was running, the air stones running at night were bringing night time o2 levels below what was available if solely relying on what was produced through photosynthesis alone during the photoperiod. Pretty obvious because of the gassing off. The significance of running the agitation in periods of trouble is that it guarantees a lower limit and should satisfy o2 needs at night in the absence of a healthy system. If there is no problem, there’s no need to deplete those levels to atmospheric equilibrium. Makes raising lily pipes moot if things are running fine post the first month onwards on high tech.

Usually stop the raised lily/airstones after the first month anyway but the thing to watch out for is the change in dissolved Co2 at startup/lights on when you remove the night time aeration. Just requires a slight adjustment (usually on ramp up time rather than injection rate).

It was just one setup though, heavily planted and unique... take with a pinch of salt.


----------



## Witcher (26 Jun 2020)

There are burned tips/leaves curling down on the 1st photo and I'd personally rather concentrate on making those plants looking fairly perfect instead of concentrating on algae - I've never ever seen algae on healthy plants.


----------



## GHNelson (26 Jun 2020)

Hi 
I don't think your aquarium is cycling properly!
*Ferts*: 15ml TNC Complete daily?
That's quite a bit of ferts!

My plan of attack would be!
Purchase some fast-growing stem plants and leave them on the surface of the aquarium, this will help mature the aquarium.
Hygrophila difformis would be my choice.
Reduce your lighting.
Reduce the fertilizer dosing to 3 times a week.
Do smaller water changes say 30% twice per week.

Try and get as much flow from the filter as possible!
hoggie


----------



## Wookii (26 Jun 2020)

I'm not expert on this having never had to deal with diatoms, but have you experimented to see if this type of diatom responds to treatment with Excel? Whilst it's not a long term solution, it may help you get the upper hand if it does respond to treatment.

If it were me, I'd get a small bottle. Turn your filter off, use a syringe to mist a small area with the initial recommended dose, wait 15 minutes, and turn your filters back on. If you see a decline in the treated area, then you can consider ongoing treatment.

I personally think high O2 levels are important to helping limit algae as @Geoffrey Rea points out, and in terms of general aquarium health - the surface skimmer will help with that, and might also assist with CO2 distribution with the increased flow. You may need to tweak your CO2 injection though when you add the skimmer - the skimmer in my tank (though a smaller tank) can make a 0.2 difference in the Ph profile - presumably due to increased off-gasing of CO2.

You are also running high light. The Chihiros Vivid puts out 5500 lumens and a PAR of 150 at 70cm at the centre of the light (if Chihiros specs are to be trusted) - that means even at 70% you're putting 3,850 lumens 105 PAR. Again, I'm no expert but that could be too much light on a two month old tank. You might want to consider dialling it down?

@dw1305 may be able to confirm, but as I understand it diatoms rely on silicates in the water to grow. I have read a number of reports online where folks have moved to RO water and seen diatoms decline - it's probably an extreme measure, but it depends how much patience you have to wait it out and let the diatoms decline naturally.


----------



## dw1305 (26 Jun 2020)

Hi all, 





Wookii said:


> @dw1305 may be able to confirm, but as I understand it diatoms rely on silicates in the water to grow.


They do, but it isn't a straight forward case of <"silicon = diatoms">.  My guess is that water always has <"enough silicon for diatom growth">, because diatoms are pretty much universal where-ever <"there is liquid water">.

cheers Darrel


----------



## Wookii (26 Jun 2020)

dw1305 said:


> Hi all, They do, but it isn't a straight forward case of <"silicon = diatoms">.  My guess is that water always has <"enough silicon for diatom growth">, because diatoms are pretty much universal where-ever <"there is liquid water">.
> 
> cheers Darrel



OK, so even RO water would have enough silicate, and wouldn't help to limit their growth vs tap water in a case like this? (I appreciate having silicate in the water won't automatically result is diatoms) I guess it could be included in RO salts as an impurity. Is what I've read correct, that diatoms are eventually out competed by green algae, which is why they tend to decline on their own in an aquarium?


----------



## dw1305 (26 Jun 2020)

Hi all,





Wookii said:


> so even RO water would have enough silicates


Yes, basically you have to get down to vanishingly small levels of orthosilic acid before you exclude diatom  growth. The level given to exclude <"planktonic Diatom dominance"> in sea water is 2 microMol  silicic acid (Si(OH)4) . The RAM of Si is 28.1, and the RMM of Si(OH)4 is 28 + 64 + 4 = 96.  So 96 g/L is a molar solution, 0.096 g is a millimol and 0.000096g is micromol. So you need to get below ~0.0002g/L of silicic acid before diatoms are impacted.

Ultra pure DI water would exclude diatoms, but RO probably wouldn't.  





Wookii said:


> I've read correct, that diatoms are eventually out competed by green algae, which is why they tend to decline on their own in an aquarium?


I'm not sure, if you have very low levels of "diatom available silicon" the diatoms themselves will deplete it, by converting it to SiO2 in the frustule. The frustules are <"potentially eternal"> at low pressures and temperatures, so that silicon, although it may still be in the tank, is permanently unavailable to the diatoms.

cheers Darrel


----------



## zozo (26 Jun 2020)

I once had it for over 6 months and i didn't give up and it did go away on its own. Never seen it back again, the aquarium is about 5 years old now...

It was the first time for me for such a long period. Don't know why. My best guess it was also a first time that i used over 7 kilo's of Mopani wood in a 110-litre tank. And the water was coffee brown for about the same period... Both the algae and the stained water disappeared around the same time. Their could be a correlation something leaching from the wood that favored the algae.


----------



## cbaum86 (2 Jul 2020)

Big thank you all for your comments and suggestions. I'm pleased to report that I am 90% over the hill with this one.

I made no changes to the general setup of the tank apart from the addition of a skimmer. Sadly I didn't have a great location for it, ideally it would have been the rear opposite corner to the filter outlet but the rotala doesn't allow for that. For now it's placed next to the filter outlet so I doubt has added much to the flow but I'm amazed at just how much muck it collects from what appeared a relatively clean surface, especially after a water change. It's a shame it looks like crap (it's the APS skim-250), nice chunky bit of plastic but I suppose it looks a damn sight better than swathes of brown diatoms.

The only other change was rather than gentle brushing I moved to brutal agitation and removal of the filaments. I vibrated my hands throughout all of the plant mass breaking up the filaments and did a constant running water change until the water looked clear - I left the filter running during the process. I did they every other day for a week and at the same time cleaned the Oase prefilter at the end of the process - it was pretty gunked up.

I've still got bits to go but it's very minimal so hopefully I'll just get those in regular maintenance/water changes.


----------



## Geoffrey Rea (2 Jul 2020)

cbaum86 said:


> I'm pleased to report that I am 90% over the hill with this one.



Nice work @cbaum86


----------



## cbaum86 (2 Jul 2020)

Geoffrey Rea said:


> Nice work @cbaum86


Not quite biscuitgate but I'm still going to celebrate with a nice drink in front of the tank at the weekend.
Thanks for your help!


----------

