Re: Competing w/Algae, and Norwalk A.S. (again)

Subject: Plants competing with algae


> I think all of us at one time or another have stated that it's g
> densely plant because "plants outcompete algae for nutrients".
> I've always felt uncomfortable about this.  Does anybody know th
> basis of this statement?  Can plants use nutrients faster, thus
> removing them from the water before algae can use them?  This se
> little far fetched.  Nutrients should be evenly distributed in t
> water column, easily usable by anything nearby.  
> I prefer the "allelochemcal" reasoning for dense planting.
> Any opinions?

Opinions?  Of course!<g>

My theory is that it's some of each (how's that for walking the 
fence?)  I think that algae is _very_ good at scavenging what ever 
nutrients are available, so I don't think the higher plants truly 
out "compete" them.  But I _do_ know thast high light + high 
nutrient levels + ALGAE.  In a densely planted tank, particularly 
one where there are healthy, fast growing species, nutrient levels 
are usually very low.  I think there isn't much left for the algae 
to use... The same philosphy that reef people use... Provide a 
nutrient poor environment, with only _just_ enough nutrients for 
your symbiotic, coraline and macro algae, leaving none left over 
for micro algae.  If there are excess nutrients, they _will_ be 
put to use, no matter how heavily planted the tank is.

BUT, I also believe in the allelochemical theory. ;-)


> Subject: new plant tank woes

> After reading up loads of useful info from this list and the arc
> decided to try my hand at a planted tank and set up a 29g about 
> The tank has two 4ft double-bulb shop lights on it with 4 40w vi
> (I think 3 of them are old, 1 is new) Mind you the tank is only 
> so there is about a 9" overhang on either side, providing what I
> some extra light to the lower side plants in the tank.


> Things aren't too
> bad but the Bacopa is growing little, if any, the H. poly is rea
> new leaves are very narrow, and the wisteria is melting (I suspe
> salt I added to fight the ich). The swords grow new leaves every
> apons are taking over and flowering. I suspect the Bacopa might 
> warm water (the tank is at 82deg due to a recent ich fight).

Bacopa grows fine even at high temperatures _as long_ as it is 
supplied with plenty of trace elements, light and CO2.  It grows 
like a weed (well, I guess that's what it is<g>) in my Discus 
tank.(temp 82-84F)

> The
> is hair algae- it's covering every plant and the glass at amazin
> The lighting is on for 12hrs straight. I find that if I wipe the
> the glass, it's back in one or two days. I do a 15-20% water cha
> week and remove dead leaves. I'm not using any fertilizers initi
> phosphates are being added (other than tapwater). Might I have e
> phosphate levels in my tap water? I was hoping the SeaChem beads
> but it doesn't seem to be. Where is this algae coming from? Peop
> I should expect an initial algae outburst around this time in a 
> but I'm afraid the plants will get choked (even with weekly clea
> I guess it's time for a phosphate test kit- any suggestions? 

The problem is that your tank is not in balance.  You have a _lot_ 
of light, but are not supplying supplemental CO2 or trace 

> Also, if anyone is in Connecticut or Mass and has any clippings
> plants they can't sell to pet shops or were about throw them awa
> I'd be more than grateful to take them off your hands- I feel si
> for H. poly but it seems I'm the only one in the world who can't
> stuff :) 

See my note to Steve Re: the Norwalk A.S. annual event on Sept. 
30th.  Maybe we can have a "Plant Digest Reunion" there!  Aquarium 
Society auctions are also great places to pick up neat plants.

E-mail me if you want more info.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA