What's the best sand substrate for plant growth?
 

Suggestions anyone?

Thanks,

Yasmin

"Sand" usually refers to a substrate with smaller particles than "gravel". Flourite has regular size particles and a "sand" version with smaller particles. "Play sand" tends to include very fine particles, almost like dust, while "pool filter sand" has particles all within one size range, somewhere around 1 mm particles.

With those definitions: the best "sand" for plants is probably Flourite black sand, because of its high CEC. Whether anyone has shown that Flourite black sand grows plants better than pool filter sand I don't know, but theoretically it should.

Sorry, this is probably a dumb question, what does "CEC" mean?

So it is not a definate that the flourite sand will grow plants better than pool filter sand?

I am planting a discus tank (switching tanks - planting new tank then then transferring the discus).

I have white pool filter sand, and was thinking of sectioning off an area that would have flourite black sand and be planted

I do not use CO2, just flourish and excel. But will probably upgrade to CO2 around x-mas time. :)

My plants are: rotala indica, java attached to DW, crinum thaianum + calamustrium, dwarf hairgrass, ludwigia repens, lobelia c. small form, e. bleheri.

Suggestions?

Thanks for all your help folks! :icon_smil

Yasmin

They grow plants about the same the only difference is the Flourite products will have trace iron in them but water column ferts will supply that so PFS works just as well - it all comes down to witch one you like looking at the best.

~

If your going to add C02 your going to have to start using a real fert regiment so it won't matter what substrate you use just as long as it's between 1mm to 3mm in size.

- Brad

I don't have any answers, but I think an important question is which ones are easiest to plant stems in.

"Cation Exchange Capacity"

- Brad

So seriously - flourite sand does not have any advantage as far as growth power over PFS w dosing of excel and flourish plus root tabs under plants???

Wow - I would love to just have the PFS...... This possibility makes me happy!!!!!!!

Can others comment to confirm this???? I would have to cancel my order of the flourite sand then by tomorrow.

Thanks so much all!!!!!

Yasmin

To expand on Cation Exchange Capacity. It's basically how effective the substrate is at adsorbing positively charged nutrients, hence it serves as a nutrient storage. Sand has a low CEC, substrate like Flourite have a high CEC.

From what I understand the difference between "sand" and "gravel" is just size and porous content. So as long as you stay in the 1mm to 3mm range (which is nearly all the substrates we use) your fine on CEC.

What Hoppy said earlier is spot on for what I've seen myself, anything smaller that PFS (like play sand's .05) becomes low in CEC and if you get above 3mm the same thing happens.

For my personal use PFS, Flourite, Eco, SMS/Turface, T-Grad Colorquartz, and SAS grow all the same with a good fert regiment + root tabs.

- Brad

Cation Exchange Capacity represents the ability of the sand particles to hold nutrient positive ions, like Fe, Mg, Mn, Ca, NH4, etc., where they will be easier for plant roots to pick them up. This is a definite advantage that Flourite has over pool filter sand. Another sand that can be used is zeolite pool filter sand, which is sand made up of particles of zeolite, which is a mineral form that has an even higher CEC than Flourite. Unfortunately, I have only found 3 zeolite sand products, and two of them are very ugly as a substrate, the one I used being a sickly greenish color.

The problem is that while a high CEC is theoretically a big advantage for plant growth, I don't recall seeing experimental results showing that it is 100% better at growing plants, or 10% better, or 1% better.

I'm currently using plain quartz pool filter sand for my two tanks.

EDIT: I just remembered one test result I have seen. Tom Barr did some testing using two, as I recall, species of aquatic plants, with a few different types of substrates, among which were Lake Tahoe silt, soilmaster select, which is a high CEC material, ADA Aquasoil, S.F. Bay Delta silt, etc. He judged the results, again as I recall, by drying and weighing the plants that grew in the substrates. The soilmaster select was one of the best, Delta silt was one of the best, and Lake Tahoe silt was one of the worst (being largely quartz sand, I would assume). ADA Aquasoil wasn't the best! These results might suggest that high CEC materials do have a significant advantage over pool filter sand.

I used flourite gravel on my 30 gallon. I was using pressurized CO2 and EI dosing of dry ferts. I was growing mostly swords and crypts. When I bought my 125 gallon and moved all my plants over, after a lot of reading, I decided to go with pool filter sand because I couldn't justify spending 300 plus dollars on "plant sand". I am still dosing EI dry ferts and running pressurized Co2. I am NOT using any fert tabs and I am getting just as good of growth from my swords and crypts which are considered "heavy root feeders"

Truth is the plants are not picky and will pull the nutrients where ever they can get them from. In this case the water column.

Thanks for your comments everyone.

The flourite sand will run me $90 + is no where near as pretty as the pool filter sand. It seems like I can invest that $ into a CO2 system in a couple months, and setup my tank with PFS, excel, flourish and root tabs in the time being.

None of my plants are especially demanding.

How does that plan sound to all of you? You can even respond "yay" or "nay" if you want to avoid repeating info or to save your time. It would still be valuable info! :)

Thanks!

Yasmin

EDIT: Also, if I use the PFS (seems like I will), should I add any nutrients to it? If so, can you please give me explicit info (including brands, sources and doses) of what I need to add to my 72 gallon partly planted, with instructions??? Geez.... I feel like I'm asking a lot!

I'm a 'Yay' except on the "excel, flourish + root tabs" idea. If your going to go C02 then step up and buy dry ferts and be done with the extra expense.

All you need is:

KNO3
KH2PO4
Trace mix (CSM+B or pfertz.com's "M")
Gh booster (for after water changes only)

from either:

[ http://www.greenleafaquariums.com/aq...ertilizer.html ] or [ http://www.aquariumfertilizer.com/in...ditU=1&Regit=2 ].

The root tabs are fine as well just a little extra boost for the rooted plants.

Hey there - thanks.

I meant to use the excel and flourish in the meantime until I set up the CO2 in december when funds allow it.

Would the dry ferts be better even know? Also, what results could I expect with the flourish, excel + root tabs as far as plant growth/health?

Thanks!

Yasmin