A question about competitive plants

Over the past two weeks I've been doing weekly 50% water changes on my tank and I 've noticed my chain swords pearling for the first time while, everything else always pearls from my pressurized CO2.

It seems obvious that I need to add more CO2 but, it also raises two questions.

1. Does this mean my pygmy chain sword is not able to use CO2 until it reaches a higher concentration? Or rather, that it has a higher threshold than the other plants? I haven't heard this talked about very concisely before so I'm not sure what terms are usually used.

2. I have a pretty large stand of water sprite in my tank.....can this actually be detrimental to the balance of the tank? A couple of my plants, including my chain swords seem to be doing better since I've been keeping the water sprite at about half its usual size. Or is this just a problem of limiting nutrients?

I've just been wonder if it's silly to keep increasing the nutrients and CO2 just to feed the WS as a fast grower to keep algae at bay when maybe I could just take it out and everything else would possibly take up the slack.

tjbuege;75288 said:

I'm not Tom, but this made me think of something... maybe your large stand of water sprite was restricting water flow / circulation, and thus limiting the CO2 and nutrients that made it to the chain swords? Just a thought.

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I was leaning towards this idea too but what was 4-5 chain swords has turned into a dense "lawn" and they show no signs of slowing down. Also, they aren't shaded by anything either.

Although if memory serves I converted both my XP2 and a 280gph powerhead to spraybars at almost the same time as I cut down the water sprite. The other plant that doing better is the pennywort in the opposite front corner.

The tank itself is three months old. It's a 40 (45?) tall with 4 NO T5's, 1 10000k, 1 6700k (HO's run as NO)and two warm white's that I would love to change out but, three ft. T5 NO are hard to find in anything else. These are centrally mounted in a 8" tall DIY hood.

I'm also running pressurized CO2 through one of those "vortex" red sea reactors which I find woefully inadequate.

Substrate is 2in of Flourite over 1/2in of peat moss.

Tom you may be exactly right with the root development idea as my pennywort wouldn't even stay planted for the longest time yet did grow some leaves. Is there a reason that root growth, in particular, can be stunted?

Also, can plants be made to pearl at a lower light level by adding more CO2? That would make sense to me but I had never thought of it that way before.

Philosophos;75327 said:

Thinking of it, a 40 gal tall is probably going to have some real fun with partial pressure... hope you're injecting the CO2 low in the tank.

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I have it pretty low. I have the water output from the reactor just a little below the intake of my XP2 with the pressure set to spit out some bubbles about once a minute which then get sucked into the intake.

Actually I just got home from work and I can definitely say the chain sword is now the fastest growing plant in my tank. The water sprite seems to be in "shock" and not growing very much but another stem plant that was growing kind of sluggish is now definitely taking off. It's like someone turned the "grow switch" on in my tank.

And while I'm happy about this, I would like to know whats going on lol.

Upon further observation (mainly of my CO2 running out for a couple days) I have concluded that the chain swords give the appearance of needing more CO2 than the other plants because they are in a lower flow.

It seems the water changes make them pearl cause that is the only way they can get the CO2 that they need.

After 4 days of no CO2 they are the hardest hit being the only plants with algae growing on them. Well, thats my assumption for now.