Just wanted to check the validity of a statement the guys at the local fish store made. They said that in a newly planted tank it takes a few weeks for plants to establish a root system, and during that time the plant disregards its leaves. Then after a few weeks almost overnight the plants leaves should look healthy and be growing out. Any truth in this?

He also said that in the first few weeks it was a bad idea to dose ferts since alge would be the only thing using it as plants are busy growing roots. (cant understand this once since nutirents are needed to grow roots in the first place)

I would assume the plant to be focusing on both since the leaves are #1 in photosynthesis so with roots and no leaves how would it survive if it only focused on one? Also since aquatic plants take up a lot of nutrients from the water column why would it need to foucs on the root system so much?

Hi,

I think they are incorrect.........and you should stick with this site


Plants take in either via the roots or the leaves and sometimes both based on circumstances and what is available.

I would say that during the rooting phase, they are MORE dependant on the leaves, and they are not ignored.


This is just plain incorrect, sorry. While the plants are busy growing roots, they need energy to do so. If you don't fertilize, where does the energy for root growth come from? Sure they have some storage, but not for 3-4 weeks. End result here IMO is poor plant growth and plenty of algae. You will have light and high ammonia from the cycle. Algae doesn't need more than that. The ferts will help it grow yes, and that is the reason for heavy planting from the start.

You are correct that many plants with smaller root systems take a lot of intake via the leaves. Think of any floating plant......

Hope this helps.

There are probably some aquatic plants that can't grow without a root system, but most of them will grow floating in the tank. Aquatic plant roots appear to be primarily for anchoring the plant and secondarily for sustenance when the body of water dries up every year. As far as it taking a few weeks for plants to grow their roots, mine seem to grow a pretty good set of roots in a couple of weeks or less. True that the roots keep on growing after that, but so does the above substrate part of the plants.

LFS clerks are not the best source of information about this hobby.

I would also think that an awful lot depends on the type of plant. Many plants basically use roots just for anchoring and not so much for nutrients. Some plants are entirely non-rooting. So to make a generalization like that doesn't seem very responsible.

thanks guys, i did not say anything to them at the store but fully believe everything i hear from you guys and take what the LFS say with a grain of salt. As from experience they are usually ill informed and going off their own presumed answers with no real testing.

Plants actively grow both locations and take up nutrients from both locations also.

What the heck does this person think when you trim plants and pull the roots up and replant tops? Should we "wait"?

Humm...........

That does not make any sense in an established tank right?
So what is different in the advice and the tank in this case?

It's a new tank, not anything to do at all with the plants themselves.........

So the plants are a non issue in both cases.

Some plants take awhile to get a strong root system going, Crypts, swords etc, and they pump a lot of O2 into the sediment which in turn fosters a better bacterial community/cycling rates, but also does not really imply anything about up take or preferences of the water vs the sediment for uptake either.

Take a look where these plants come from: rivers.
These rivers vary in level so the plants are high and dry in the Dry season, and submersed and subjected to high current during the wet season.

So they need strong root systems to avoid being swept away and also for uptake when the water column is no longer present. We do not have such velocity or water level changes in our tanks however.

I think someone wants to say things without any real evidence that what they say is true, they have not set up any test to see if what they say is true based on observations. Then after saying it awhile, they convince themselves that it's really true and have not asked themselves the right questions and had enough self doubt.

So it might at first sound plausible, but not if you think it through.
This is how a myth gets going and is hard to stop.
It's also understandable that hobbyists might think up stuff like this also.
Still, I keep after folks to try and think through things and see what they can do to answer, rather than merely speculate.

We know the nutrients are not limiting algae in all cases.
So that's been ruled out.
That's pandering to fear and myth.
We also know they have never set up a test to see if the claim is true or not.
So that's 2 strikes in the logic.

Next we draw from simple observations for plants and removing the roots/cutting them off and noting the rates of growth. Cedergreen and Madsen did this under controlled conditions with a nutrient rich water column and found no differences in growth for 3 species of submersed aquatic plant.

Now we can and also do this same thing, sometimes weekly, when we prune/trim stem plants. Do these plants get covered with algae and stop growing? No.

If I really uprooted everything, or if I had a new tank, then perhaps.
So it's not the plants really, it's something in the uprooting(pulling up NH4/organic material that lowers O2 levels) and the bacteria.

New tanks: no bacteria established/NH4
Big reworks: less bacteria/NH4 pulled up

These are two pretty common things and they also match observations/logic and match well in explaining the plants and algae issues in pretty much all cases.

Including trimming/pruning, replanting tops etc.

I trim and replant weekly: Tonia, Blyxa, L pantanal, Cabomba, dozens of species and they grow 2-6 inches a week.

If plants slow their shoot growth down to produce more roots, I sure do not see much.

I do note differences in growth in a new tank or one that's had a big rework.
Bacteria and establishment play a large role, something you cannot leave out.

Regards,
Tom Barr

thanks Tom your wealth and breadth of knowledge never seems to stop astounding me

Also your ability to type all that in a few minutes time is impressive

I suppose if I spent more time googling and editing things, folks might think I was a fake when folks can respond fairly quick, they have thought about it pretty well in general.
On the web, some folks can come across pretty sharp, but dumb as a box of rocks if you take their Wiki and google resources away, hehe. Funny how copying other folk's stuff can make you look smart but then not so smart later.

I've heard this same stuff before.

Regards,
Tom Barr

I've seen a lot of forums in europe, Lots off information, but usable???? Lots of peolpe think they have the knowledge about keeping plants in a tank and keep algea away. The problem is : what do i have to believe and what don't. I've went lot of advised strategy's but nothing seems to "fit"on my tank. Then i came (linked on apc) on this forum . I've not seen that knowledge on any forum in The netherlands , germany belgium etc. After big problems with my tank , i can smile again , thanks to you guys. You talk sense!

Well "Information is not knowledge."

The web and parroting what others say is a classic example. All are based on giving you (mis)information, but it's not knowledge, it's placing doubt that sounds good, but it is truly lacking logic if you really consider it. No critical thinking.

Tell folks what they want to hear.

The truth is often messy, unknown, many areas of grey, questions left unanswered.........one is answered, even more questions arise from that answer.
It's easier to be in denial and live the lie

We all are human and make mistakes, knowing this, we can set up methods(such as using some tenants of Science) that verify whether we made a mistake at each step in the process. This way we can be pretty sure we get the right the right answer for the question.

I just know how feeble minded and incompetent I can be at times and knowing that, I make sure to check everything again and again. This way I'm sure I did not over look something in arrogance.

Doing research is very humbling, you feel pretty dumb and often times the answer and solution are staring you right in face. I make lots and lots of mistakes, that's why I know more and am willing to admit and talk about the human nature side of all of this.

But we do not simply give up, and think of ourselves as too dumb to figure anything out, rather, we set up test, calibration of test kits, double check things, add a control to compare the results too, go back and see if we can induce algae based on some hypothesis, see if we can induce Ammania to stunt by adding high levels of K+ over time.

If someone claims that high levels of K+ cause stunting in a certain species, then we should all be able to repeat this with a healthy growing plant as a reference.

This seems logical?
Does to me.

When I hear such things, even if they are from Amano or credible folks, and I cannot induce the same responses, I have to question if there was something else, some other interaction they did not consider. However, while I might not find out or show what they did that caused the stunting in their case, I know that K+ in and of itself cannot be the cause directly.

Another issue is when folks say high levels or low levels, what do they mean?
30ppm K+? 50 ppm K+? 100ppm K+?
We should be specific about the plant, the light, CO2 and the parameter.

Vague talk about concentrations typically means they have not bothered to test them well, nor have explored the parameter under any sort of controlled condition.

They can report their findings etc, but they cannot say anything about cause/effect, just some correlation at best. Still, many try to do so.

Regards,
Tom Barr