'Egeria Densa' the nemesis of blue green algae?!

[gary35111]

Hi guys,

I was exploring this tropica website trying to identify the new aquatic plants I bought and guess what? I came across this plant, 'Egeria Densa'. And when I read the information of this plant, I was like, "Wow! I must have this plant!".

:p I am quite a newbie at aquatic plants and to play safe, will always purchase the 'easy-to-grow-consume-minimum-CO2' type of plants. I have just moved all my CRS and rest of the livestocks except snails from my tank to a makeshift one. They would have to stay there for a week or so. I am having this battle with green spot algae growing on my glass tank's wall. With all the red ramshorn and clam snail and my "golden white snail" (Not apple), the green spot algaes are still there! *Sigh*So I bought more plants and sort of cleaned up the wall, revamped and renovated the interior whole of my tank.

And just when I am all done after hourSSS of trying to get these stupid plants reasonably firm and grounded in my ADA soil; I had my shower, was sitting comfortably in front of my PC drinking my hot milo and trying to find more information on-line regarding the new plants I bought... :shocked: I came across this 'Egeria Densa'! Why do I only come to know of this plant now!

I am equally pissed >( and happy :D . For if this plant is as what the information says, that it actually secreate a substance which kills and prevents blue or green algae then wala, my battle with green spot algae will be near victory with this plant...but...that means I will have to buy these plants and to replant it again....I am now lazy...so and too tired of planting...This is why I am pissed.

Now I have to go back to my aquarium and see which plants should say ciao to make space for 'Egeria Densa'. But then again, I want to know more about this plant from the experts here or anyone who have had 'Egeria Densa' before. Does it really work against algae? And I mean green spot algae? Also, the substance it secreate, will it be harmful to CRS? If it is not that good then I would rather just stay put with the plants in my tank now... :undecided for now...

Thanks.

(Oh man...after so many hours...now let's see which plants should my tank says sayonara...)

[fatboy]

I use egeria densa (also called Elodia densa) a lot as it's by far the most readily available plant over here. It survives outside, even when it freezes, is a great oxygenator and doubles in size every month under good conditions. The stuff I can buy is usually called 'densa' but might be another very similar species.

It's a great plant. It's used as the main plant for many coldwater tanks and has a reputation for preventing algae by out-competing for resources. In my experience it DOES seem to slow the growth of green spot algae.

I don't know how well it would do in warm climates. E. densa is from Brazil but it stops growing and tends to die off in a tropical tank (anything 75 degrees or above).

I'm going to plant some in my dwarf puffer tank and see how things go. that tank gets direct sunlight and gets covered with greenspot algae within a week.

Edit: here's a pic of my tub with some egeria densa for snail breeding. It gets no direct light and is floating in old tankwater, covered in snails (100+).

http://img266.imageshack.us/img266/9319/elodia4ja.jpg

[silane]

Thank for sharing, now I know this common plant has unusual property suppressing Blue-green algae is bacteria.

[gary35111]

Thanks for the reply! In Singapore, our temperature can go up to 30 + degree C and I suppose it may not do as well for Egeria Densa as compare to in UK.

Anyway, for those living in Singapore and want to get these plants, the 24 hrs Clementi Blk 328 Polymart is selling @ SG$1 cheapie cheap lol . They looked like hydrilla, I asked the attendants if they are hydrilla, they say no and have no idea what it is. :) But the plant sure look identical to the picture of 'Egeria Densa' posted here and in Tropica website. I just got mine and have (with much difficulty) planted them in my tank. I only use half of what I bought as I read that they grow real fast. Planted a few near the tank wall and as background.

Our good friend in UK (or anyone here with experience on 'Egeria Densa'), do you know how long does it take for 'Egeria Densa' to root itself firm to the gravel (ADA substrate)? Maybe it is with my ADA gravel or just me, I had a hard time trying to get them in the gravel and they still look kind of 'shaky' like going to float up any second.

Gary

[NanoDave]

where is selling? :) Is this the same one that lfs usually have lots and lots of?

[simcb]

I used to have keep this plant when i am in australia and they are not very fast growing in my tank. Not really cheap $5 aus but easily available. I still get BG algae and stuff, maybe i over feed those white cloud minows lolz. So i am not sure is the algae control thing true? But i would really want to try it in my shrimp tank, if it helps remove NO3 and prevent the growth of some algae.

Very interesting and thanks for sharing.

[retardo]

This is the first I've heard of Egeria Densa secreting a chemical that suppresses the growth of Green Spot Algae. I used to keep this plant in my tank at 78deg. Once it rooted itself (not very long), it grew like mad and a I would have to trim and dump the cuttings once a week or replant the tops. I had so much it covered 25% of the tank. I haven't had any problems with green spot to date.

[simcb]

This is the first I've heard of Egeria Densa secreting a chemical that suppresses the growth of Green Spot Algae. I used to keep this plant in my tank at 78deg. Once it rooted itself (not very long), it grew like mad and a I would have to trim and dump the cuttings once a week or replant the tops. I had so much it covered 25% of the tank. I haven't had any problems with green spot to date.


Wow. I had a problem getting this plant to root with those gravel which is slightly bigger often used for undergravel filter setup previously.

Maybe i will go get a stalk or two to test it out on ADA soil. Lately my shrimp tank is getting this odour and algae is coming back even with frequent water changes maybe because the shrimp population has x 2 times :D .

[Robert]

Hi,
this stem pant is a real water plant, so it does not need its roots too much. The roots are just there to hold the plant on a certain place. The plants can take up nutrients over its whole surface.

This Egeria densa is not a native plants of my region but I can find it here too because it's a neophyte. I kept it once but don't like it too much. There are a lot of easier to grow plants and there are also plants which can take up nutrients faster and better e.g. Lemna trisulca (a cold water plant).

The problem with the green spot algae can be solved in another way. There is a problem with the balance of light, CO2 and organic e.g. nitrate and anorganic e.g. iron nutrients in your tank. There is something missing or a surplus of a certain factor. I suggest to measure all necessary parameters (pH, KH, nitrate, nitrite, Ammonia at least), take a picture of the tank and post it here. Often there is too much light, too less plants, too much fertilizer and too less CO2. It is possible to find a balance and if you reached it, the tank will be almost free of algae. But the tank must be well aged and cycled before and you have to know what you do. In my show tank for example I clean the glass every 3 or 4 months from algae. In my shrimp tanks it is not necessary to clean the tank from algae at all, there are no visible algae.

regards

Robert

[Herbie]

I had a tank that had a lot of BGA in it. I added densa (it grows like crazy in a CO2/high light tank) and increased circulation by adding another powerhead. All of my BGA was gone in two weeks. Not sure which one fixed the problem...maybe both did :)

[Jane of Upton]

Hi Gary,

is the tank with the green spot algae (GSA) relatively "young"? I've found that GSA is often a part of the initial break-in period, coming at the tail end of the tank getting established. If it perisits, then look into your water parameters for the reason it is thriving. I've had it in about 1/2 the tanks I've set up, and it usually disappears after a few weeks. I think the snails may eventually eat it, as they graze out the "yummier" things, and move on to the GSA.

Lots of plants (and algaes, too for that matter) secrete what are called allelochemicals. These chemicals are generally targeted at other species, but sometimes will affect their own species. The classic example is fruit trees. They will inhibit the growth of young saplings underneath an established tree (which will keep the older tree from having competition). But once something happens to the older tree (it gets cut down, or knocked down in a storm, etc.) then the suppressive allelochemicals stop being produced, and young trees emerge to take its place.

The succession of algae blooms throughout a season is due in part to allelochemicals. The secretion of an "earlier" bloom are sometimes found to actually enhance the growth of a "later" bloom.

Egeria densa (and Egeria crispa, which I find much more attractive) is a good algae buster not only because its a fast grower, but becuase of its allelochemicals. Another plant that I think has wonderful algae inhibiting qualities is Hornwort, (Ceratophyllum demersum). I set up a small 5.5 gal tank recently, and forgot to add any hornwort. I noticed a few bits of a tuft algae on some gravel, and put in a sprig of hornwort. Two weeks later, there is none of that type of algae visible. It can be floated, and will form anchoring roots (not nutrition-deriving roots). I usually keep at least a bit (5" long branched piece) floating in all my tanks for its anti-algae qualities.

Now granted, these plants can't eradicate an all-out plague, but if other conditions are kept to NOT encourage algae, then these plants can be an additional effective tool to keep algae from gaining a foothold.

The specifics of what inhibits what is VERY difficult to prove scientifically, as when two plants are together, you can't stop production of allelochemicals from one and take measurements just from the other. Not to mention that many, many differenct compounds are being made, not just a single, isolated allelochemical. Plus, bacteria, diatoms and other microorganisms are having a constant effect, breaking these compunds down - both in the water column, and the substrate. So, it is an extremely difficult thing to quantify in any scientific way. But, anecdotally, these effects have been noted for quite some time.

I think its just one more wonderful tool to put to work in our tanks to keep algae at bay.

-Jane

[sandiegoryu]

I would say no, at least in my experience Egeria densa does not "attack" bga. I also heard on tropica that hornwort will also "attack" bga. I had bga, and it would SMOTHER my Egeria densa... So when I heard of the hornwort, i bought that. The bga smothered that as well!! Also GSA did not go away as well. My tank was full of BGA! I even used erythromycin and that did nothing... Only make a few bubbles pop out of bga, meaning it's a little weakened. Then I left town for a week and then viola! GSA and BGA GONE! even all algae ceased to grow. Now I don't have to clean my glass at all. I believe it might have been the part where I didn't give any food for the fish for a week. Maybe... not sure. But it worked! Well thats my experience with bga and gsa. Now I have staghorn. Not sure if it even IS staghorn. Looks like hair algae but red...