Please do not cross post in multiple forums.


Flourite and eco complete can both be used as is. You do not need to use a first layer substrate like laterite. There are some stuff you can add that will help: mulm from another tank, a thin layer of peat, root tabs.
Liquid ferts in the substrate will just end up in the water column.

 

Tony,

Out of interest, what plant tabs are in use (Jobe Sticks I know of - but others?). Do they all have more or less the same effect, are there some special focus chemsitry with some makes? If undisturbed, presumably there is no risk in leakage of tab material into the water column. If disturbed, is the resulting leak into the water likely to be highly problematic in terms of algae propogation? Would you reserve use to certain plants? Picking your brains here...

Andrew Cribb

 

Jobes have had associated green water and other algae blooms when pulled up or not placed down deep enough when replanting etc.

If they made them without NH4/urea, they'd be fine for tanks.
Many use Flourish tabs.

Plants will not use substrate nutrients generally unless there are none in the water column.

the substrate is typicalkly a back in case you forget to dose the water column, or you can use the substrate as the main source but make sure you re-enrich it regularly and there's less way of knowing when the nutrients are low.

Regards,
Tom Barr

 

Plants will not use substrate nutrients generally unless there are none in the water column.

So your saying plants won't root feed if they have sufficient water column nutrients. What about all the rosette plants? I also thought that Fe was most easily obtained by plants throught their roots and that Fe was often in a form most avaliable due to the redox potential of many substrates. Isn;t par tof the reson for peat to add this redox and make nutrients more avaliable to the plants roots.

Sorry Tom, not meaning to sound like I doubt you, I just am starting to get into the substrates more and still trying to learn

 

Yes, submersed aquatic plants will take from the water column first if it is available there.

It does not hurt to have Fe, Mn, a good bacterial culture going down there etc.

Folks will often forget to dose.

Fe etc, needs first reduced, then brought inside the root cell, then needs chelated inside the plant by it's own form of chelator to translocate the Fe to the stem/soot. The plant can do this just fine on it's own on the roots(NOT the stem/shoot), so does not hurt to have it down there.
Adding the Chelated forms of Fe to the water column allows the plant to get enough Fe from the water column in it's reduced form.

The main thing I believe that helps Aquatic plants with Fe in the substrate: roots need Fe too, so then the reverse situation may occur, the plant has to take the Fe from the water column and translocate it into the root system.

Having Fe in reduced forms in both places allows the plant to grow well/better in both places even if it does not need to derive any nutrients from the substrate. At least this is my notion about it. Still, I've found that thi is true from some plants, but not the ones people always claim are "Root feeders", Swords and Crypts.

Bacteria also play a role in cycling of nutrients and fungi as well.

Many plants produce lots of roots no matter what, but whether they are contributing or not to nutrient uptake is a COMPLETELY other matter.

That is one thing many plants cannot shut off, but they can allocate resources within the plant itself for growth.

Also, water column nutrients do premeate the substrate and nutrients in the substrate diffuse much easier into the water column than many would like to believe.

So trying a substrate out with zero nutrients in it(and also very little bacteria etc) is a good way to get a good a handle on the water column dosing and also the effects of addition to the substrate.

I've never ever had any issues growing crypts and swords to the point of weeds in my tanks without any substrate fert's.
So if this is true, I seem to have done something that is couter to what the popular dogma suggest and I've not seen any evidence to prove their point correct to date, I've found evidence to show my contention and observation is correct on the other hand.

Regards,
Tom Barr

 

So what plants have your experiences shown to be heavy root feeders. I wonder if the biggest difference in your tanks is the CO2. Even you low light tanks are CO2 enriched, correct? I have noticed in my limited experience that if Crypts and Echinodorus get high CO2 levels, they grow like mad.

I am starting to figure that if plants don't always use the roots for nutrient uptake, then substrate ferts would be a wonderful backup. Even dosing every day and in good quantity, there still seems to be a point where many of use start developing deficencies. Especially in high light tanks. If water gets out of wack a littel then theere is stil the substrate for the plants got easily access so the tank is less likely to go to hell. Atleast as fast. Am I right in this thinking?

 

Depends on what you mean by base fert. The only measurable mineral Flourite provides is iron. Eco Complete on the other hand contains every trace mineral that plants need. Seachem recommends adding their Flourish Tabs to Flourite. These contain 20% calcium and some nitrogen, phosphorus, potassium, and some minerals.

Like any clay product, Flourite draws nutrients from the water and holds them for plant uptake. So whatever is in your water will get to the substrate eventually, but the plants will probably absorb the nutrients from the water through their leaves before it reaches the substrate. I know Tom will disagree with me on this, but many plants respond very well to nutrients in the substrate.

There are different approaches to feeding plants. Some people like Diana Walstad favor feeding thru the substrate instead of the water. If you want to follow such an approach, then you would need to add something to Flourite.

 

Depends on what you mean by base fert. The only measurable mineral Flourite provides is iron. Eco Complete on the other hand contains every trace mineral that plants need. Seachem recommends adding their Flourish Tabs to Flourite. These contain 20% calcium and some nitrogen, phosphorus, potassium, and some minerals.

Like any clay product, Flourite draws nutrients from the water and holds them for plant uptake. So whatever is in your water will get to the substrate eventually, but the plants will probably absorb the nutrients from the water through their leaves before it reaches the substrate. I know Tom will disagree with me on this, but many plants respond very well to nutrients in the substrate.

There are different approaches to feeding plants. Some people like Diana Walstad favor feeding thru the substrate instead of the water. If you want to follow such an approach, then you would need to add something to Flourite.

No, I don't disagree
I just say that you gain nothiong in adding substrate fert's other than approaching a personal habit issue with dosing or neglect(on purpose or otherwise).

You don't gain any algae control. Yes, I've had the same algae control in similar low light high CO2 tanks with lots of water changes as I've had with non CO2 approaches.

I'll disagree with the comment EC is better than Flourite.
Ca, N(NO3 in this case), K+ are almost always taken in from the water column, I use onyx which works well and has Ca in my non CO2 tanks.

If you do water changes at all, then Ca is well supplied unless your tap has none but then you have to add it anyway.

PO4 is another matter than gets into bnding sites and various forms of PO4 and Fe. The small amount of PO4 can be added from above or come in the form of food waste etc or tap water or dosing.

I've added mulm and peat to onyx and have had excellent results, as good as any I've seen in a non CO2 tank.

In a CO2 enriched tank, the contents in the substrate matters less due to increase uptake rates and dosing, water changes etc. These differences can be used to your advantage depending on your goals and habits.

But bouncing back and forth wwith various methods between a low production rate non CO2 method and a high production rate CO2 enriched tank often confuses people. Very few people understand and can excute both methods to a high level.

Regards,
Tom Barr

 

So, plants prefer P uptake from the water column? I recall reading in Walstad (and backed by what seemed to be a well-executed experiment) that plants prefer root uptake of P.

 

No, they don't have a choice but to take it up via the roots because that's where the PO4 is in many ecosystems.

If the plant is given PO4 in the ortho SRP form in the water column, you can watch the removal rate in a matter of hours with a good kit.
You can see the plant's response within minutes also.

That's the practical.
You can try this to see and make your own choice.
You can try to add it to the substrate also and see how well that works.

These are things I have done myself.

Research done specifically on nutrient rich water columns shows that the plants will take the nutrients from the water column rather than the substrate. Much of the research is looking at PO4 limited water columns in terms of the plant's needs.
So that research does not answer the question in terms of an aquarium or plant, but rather that specific body of water, which often are PO4 limited in the water while PO4 is often present in the sediment.
So this research tends to be basis to PO4 sediment uptake, rather than "preference".

The biomass was the same even when they cut the roots off the control plants.

So if they prefer it, how could the biomass growth rates be the same for the plants without roots? This research does allow you to answer that question.

Doesn't make sense both in terms of the practical test you and I can do and the research evidence either.

You can try and add PO4 to the substrate and limit the water column vs adding it to the water column if you want and see this for yourself.
I've done this.

So while well supported in many folk's view, there are still issues and other sides to assertions/arguments made. Other more specific research, some of which is after she wrote the book, also has come to light.
The prevailing notion was PO4 caused algae back then as well..........
Steve and I changed that.

Regards,
Tom Barr