crypts and co2

[roadmaster]

I wonder if plant's that receive no nutrient's via dosing,might develop stronger root system's if substrate is primary source of nutrient's.?

 

[Guest]

In many cases either/or works just as well and there is plenty of anecdotal evidence posted here and elsewhere to support this - but it really depends on the species and its particular niche adaptations and phenotypic plasticity etc. But overall, and if there is any doubt, it remains sound horticultural practice to feed both locations - especially in the absence of relevant research on all 400 or so species of macrophyte.​

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With regards substrate leaching nutrients in to the water column I think that's a two way door. I strongly suspect that eventually nutrients will stop leaching out of the substrate as it becomes exhausted and the substrate in turn will become a net importer of nutrients - if it has a high CEC like Amazonia. But the net flux will probably vary for different nutrients, not least due to demand.​

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This is another reason why good flow and distribution are so important, it helps to drive nutrients from the water column in to the substrate where they also become available for root uptake regardless whether a substrate is inert of not - so in other words by dosing the water column we are inadvertently supplying plant roots with nutrients as well. I think this particular mechanism is often overlooked.​

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Conversely, I also think that the nutrient contribution made by dissolved solids etc in tap water, and from fish food is underestimated in many cases - even Walstad type tanks may get a fair amount of inadvertent water column dosing. Overall its entirely possible that in one way or another we've all been feeding both locations without necessarily being aware of it...​

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...What was the OP's question again...I've kinda lost track...Oh yer, it was about CO2. Definitely go for it...you'll have a carpet in no time. Oh and don't forget to dose.​

 

[roadmaster]

I don't know about crypt Parva as carpeting plant. It is by most account's slow growing, and those I have in my low tech tank are not very fast at all at sending out runner's. Eleven small pot's I planted took nearly a year to grow enough to even notice a change in overall size.
Perhap's someone has photo's of what this plant can do with CO2 and moderate light? and tell us how long it took to achieve a carpet effect.

 

[Mick.Dk]

What a discussion we got out of this 😛
I never said anything about co2 versus root tabs ..............
Commented specifically on C. parva, since I've done tests on, why this sp. didn't grow as fast and easy as other Crypts in my care.
All C. parva grown with added co2, but different light and nutrient levels.
Conclusion ; C. parva grew a lot faster, sending far more runners, when given heavy doses of root tabs and a little more light, than what I usually get away with, growing other Crypts ( mainly wendtii types, admittedly )
Hope this explains, what I actually recommended!
Mick.

 

[Mr P]

thanks for everyones ideas,i will be rescaping the tank soon and I do want to use the crypt parva I have so I will put some osmocote pellets under the crypts so they get the best of both,i will be using co2 and el and will see how they get on,
roy.

 

[Mark Nicholls]

In nature, many Crypts spend an equal time emerged and submerged. This annual change, caused by the rainy season, is the main reason why crypts melt because they have to grow new leaves which are adapted for optimal nutrient uptake. The ONLY constant is the roots which DO grow massive, both to anchor the plants and to absorb nutrients.

 

[Mark Nicholls]

I've uprooted Crypts to divide them and found extensive root balls wrapped entirely around clay root tabs despite being in nutrient rich water. This is further evidenced by Crypts growing fine aerial roots when grown in a low fert substrate. If they absorbed the lions share via leaves, aerial roots would be redundant. This ONLY happens to Crypts grown in inert substrate and doesn't happen in soil. I still claim that at least 75% of nutrients are taken from the roots.

 

[erwin123]

recently i pulled out some C. Wendtiis with extensive roots from my tank to make way for other plants. I decided to plant some it a tiny glass pot. The submersed leaves wilted and within a few days, the first emersed leaf appeared. I'm surprised how fast it took. some of the old submersed leaves are still evident in the photo.