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From the Algone website (http://www.algone.com/fertilizer.htm)

Next to a suitable substrate, light, CO2 and pH are far more important than any fertilizer.

Light is needed for plants to produce energy by photosynthesis while CO2 helps plants utilize the nutrients required. Plants will not be able to utilize nutrients and light at low CO2 levels.

Low light and CO2 levels can not be compensated by adding fertilizers. The added nutrients will not be utilized by the plants but readily accepted by naturally present algae spores.

Using light and Co2, the plant creates carbohydrates and oxygen (photosynthesis) while the pH level determines the solubility of the nutrients. A pH above 7.3 will cause most plants to lose their ability to utilize many essential nutrients. Next to that, most nutrients precipitate out of solution and can no longer be absorbed by the plants. The pH should therefore be kept at 6.5 - 7.0 for optimum plant growth.

Before adding any fertilizer the CO2, light, and pH levels have to be checked and adjusted accordingly.

As a general rule, the lighter the green of the leaves, the greater the rate of oxygenation, the faster the growth rate, and the higher the requirement for nutrients.

The composition of nutrients is conveniently divided into macro and micro nutrients. Macro nutrients are needed in larger quantities while micro nutrients are sufficient in smaller quantities.

Macro nutrients are calcium, sulfates, phosphates, potassium, chloride, sodium, nitrogen and magnesium. These nutrients are provided by fish and fish food in ample supply. Macro nutrients do not need to be added frequently, if at all, as they will be mostly replenished through water changes.

Essential micro nutrients such as iron, manganese, zinc, boron, copper, cobalt, and molybdenum on the other hand have to be added frequently. The main function of these nutrients is the promotion of growth hormones, photosynthesis, cell development, plant metabolism, and nitrogen assimilation.

The assumption that plants take on most nutrients through their leaves is incorrect. Leafs absorb CO2 and release oxygen. Essential nutrients such as iron, phosphates and nitrates are readily absorbed by the roots under anoxic conditions found in the substrate.

Plant fertilizers are available as liquid or substrate fertilizers. Both should only contain the micro nutrients. Aquarium PhotoLiquid fertilizers have to be dosed more frequently; substrate fertilizers will last longer. Since there are no obvious differences in efficiency, it is up to the aquarists' preference which to use.

Next to the micro nutrients, fertilizers contain chelates. The chelate is an organic molecule which binds metal ions thus protecting them from early precipitation. The preferred type is abbreviated DTPA because of its stability up to a pH level of 7.5

Unfortunately some fertilizers contain the chelate EDTA, which is much cheaper. However chelate EDTA is only stable at a pH up to 6.0 and therefore mostly useless in aquariums.

Another important yet often overlooked aspect in using fertilizers is water conditioners. Many conditioners eliminate heavy metals and since many micro nutrients are metals, plants can be deprived of essential nutrients despite the frequent addition.

Fertilizers can be made at home or bought commercially. The home version is known as "poor mans dupla drops" (PMDD)* relying on the following ingredients:

2 Teaspoons potassium sulfate
1 Teaspoon potassium nitrate
2.5 Tablespoon hydrated magnesium sulfate
1 Tablespoon chelated trace elements mix

The trace element mix should preferably contain DTPA chelated Fe (7%) B (1.3%) Mn (2%) Mo (0.06% Zn (0.4%) Cu (0.1%)**

Mixed with 1.5 cups of distilled water, the mixture can be stored in the refrigerator.

The required dosage varies depending on plant quantity, growth levels and aquarium size. The correct amount has to be determined by trial and error i.e. starting with a few drops per 10 Gallon while monitoring the iron and nitrate concentration. Iron should be around 0.1 ppm; lower levels also indicate the depletion of the other trace elements. Nitrates should be kept around 5 ppm. Nutrient deficiencies are described in detail in our plant health guide. Algae growth is an indication of excess nutrients in the water column.

Adding fertilizers to promote aquatic plant growth should be considered in medium to heavily planted aquariums. A few plants should do fine without.
Fish waste should provide sufficient nutrients. Fish waste in combination with regular water changes to replenish nutrients, will serve as "organic
fertilizer" and any addition of fertilizer may lead to algae problems.
* Ingredients can be obtained at chemical supply stores, trace element mixes are often available in aquatic stores.
** Fe (Iron) B (Boron) Mn (Manganese) Mo (Molybdenum) Zn (Zinc) Cu (Copper)

__________
"To steal ideas from one person is plagiarism; to steal from many is research."
researched from Steven Wright

That's good info, thanks for sharing the link/text.

I guess I never realized that ph played such an important role for the plants as well :%)...that might be part of my recurring cyano issue in my 20 gallon *shakes fish @cyano*

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Bob,

That's a great read. I will save this one for a while as a reminder.

I know this is a smaller concern, but my tank's temp is usually between 82 and 84F. Does this affect their growth, or dosing?

My Scapes

Thanks alot for the usefull info.


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The article sounds quite dated. The PMDD method was brought up almost 10 years ago and as since been pretty much `dis-proven`.
A lot more research has been done since. The phosphate limitation thing has pretty much proven to be hokum. I regularly add phosphate now and get a reduction in algae rather then an increase.
Apart from that all sound advise , especially

Low light and CO2 levels can not be compensated by adding fertilizers

Tetratech,
For the most part your temp is fine. It may slow growth a tad but apart from certain plants that require cooler water shouldn`t be an issue. Madagascar Laceleaf would suffer badly and I find that ferns and mosses don`t do their best in higher temps.

Last edited by bensaf at 21-Jul-2005 17:03

Last edited by bensaf at 21-Jul-2005 17:04

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

Bensaf,

Thanks on the temp info. I do struggle somewhat with my javamoss, maybe I will lower temp a few degrees. I have javamoss in a 12gallon guppy tank with 13watts and it looks really healthy and full, in my tank with all the fixings it does seem to grow very slowly.



My Scapes

Plants sure don't prefer root uptake, I have 1/2 dozen published research experiments to prove it.

There's all sorts of issues with that article.

Much of which was never tested nor reviewed(which I actually have done), otherwise they'd have different conclusions.

Regards,
Tom Barr

Plants sure don't prefer root uptake, I have 1/2 dozen published research experiments to prove it.

I would be really interested in reading those if you could give more info. I am looking at a subscription to your site when the funds are available to me so if I will need to do so before I can read more of that I will be happy to wait. From browsing what I can of the site I liked the Estimative Index especially. Looks like a very informative resource.

Re PMDD: I was looking at giving it a try for my newest project, probably buying supplies from Greg Watson's site because I really like the prices. I think it will save me a lot in the long run compared to buying commercial preparations from a local store like I have been. Has anyone used his premixes? I was specifically looking at CSM+B Plantex and PMDD Pre-Mix. $20 for 2 lbs of dry ferts looks like an excellent buy.

trys,

You`d be better off buying the dry ferts kno3,kh2po4,possibly pottassium sulphate and directly add using the estimative index. As mentioned the PMDD formula has proven to be lacking.

The Plantex CSM+B would be fine for micros.

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

You`d be better off buying the dry ferts kno3,kh2po4,possibly pottassium sulphate and directly add using the estimative index. As mentioned the PMDD formula has proven to be lacking.

I knew someone was going to say that. Now that I have given it more thought I think I would apreciate having more control over the individual components of the mix rather than blindly dosing the premix. In this way I think it would be better for me to buy the individual chems so that I can tailor my own mixes for individual tanks with different needs.

Now I just need to check the local hydroponic supply for prices and see how they compare to [link=these]http://www.gregwatson.com/products.asp?cat=8" style="COLOR: #36af30[/link].

Thanks

Bensaf, I need a little help, you mentioned above that you add phosphate and yet has a decrease in algae, can you give me info how's that gonna work? I've read an article about that but I'm still confused. As you know the tank in my resto is having problem with algae, it's much better now since the last time you saw it, but the algae is still there. And I noticed that I have a rather high amount of phosphate in the tank.

Andy,

The adding of phosphate alone is not going to cure anything.

The EI method works on the deceptively simple process of ensuring thatthere is sufficient quantities of ALL nutrients required by plants available in the tank at all times. Basically making sure no nutrient bottoms out.

The notion that an excess of nutrients causes algae has been pretty much dis proven, rather a lack of one or more nutrients will slow down plant growth but as the same time leave the tiny tiny quantities that a single cell entity like algae needs. Algae doesn`t need excess nutrients - it only requires a miniscule amount and stalled plant growth to flourish.

Green spot algae on glass or leaves is an indicator of PO4 deficiency.

From@what I saw you of your tank, this was not an issue so you are probably correct that you have sufficient PO4. I know you have enough light and add co2, and I know you add a lot of micros. I`m guessing you don`t add NO3, this may be the problem.Having a decent level of PO4 really speeds up the plants intake of No3.Chances are your NO3 has bottomed out.

Ideally the ratio of No3 to PO4 should be about 10:1 i.e. 20ppm no3 to 2 ppm PO4.

Check co2 aim for 20-30ppm. Nitrates 10-20ppm - increase by using KNO3.PO4 1-2ppm. If your GH is above 3odh you have enough Calcium and Magnesium.Micros I`m sure you already add.

I would check co2 and nitrates and add as neccessary.

I have tons of KNO3 if you need some. I`m still in Europe but will be back to Jakarta end of this week

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

Ashura, sorry to jump right in

Here's a link to the Estimative Index article.....I think it should be required reading.

[link=http://www.barrreport.com/forums/showthread.php?t=1]http://www.barrreport.com/forums/showthread.php?t=1" style="COLOR: #36af30[/link]