Which gives more PO4?

[GaspingGurami]

Since I have a small tank (20L) with high bioload, I'm thinking of deriving my PO4 from fish food than from dosing KH2PO4. A bit scared-scared with dosing oredi lah.

Also when talking about rice grain's weight of KH2PO4, are you chaps taking reference to those long grained Basmati rice or those short grained Japonica rice? And where do you find a scale that weigh such a light weight? The Post Office?

So I think, mebbe I can escape with feeding fish food to get the PO4.

Question is, which will give most PO4? Live food or frozen food or dried flake/pellet? And when comparing composition, am I correct to look for types with higher protein composition will give more PO4?

Thanks.

[vinz]

Hehe... you dosing from Tom's guidelines?

If you want numbers, here goes:

Mix 1 flat tablespoon of KH2PO4 with 250ml of water. Add 1ml of this solution to 40litres of water to raise approximately 1ppm of PO4.

Coincidentally, the formula for NO3 solution using KNO3 is the same.

[GaspingGurami]

[quote:664626f78f="vinz"]Hehe... you dosing from Tom's guidelines?

If you want numbers, here goes:

Mix 1 flat tablespoon of KH2PO4 with 250ml of water. Add 1ml of this solution to 40litres of water to raise approximately 1ppm of PO4.

Coincidentally, the formula for NO3 solution using KNO3 is the same.[/quote:664626f78f]

Thanks Vinz

BTW, I noticed that after mixing KNO3 with water to make a concentrate, the glass bottle feels very cold! Some kind of chemical reaction is happening I'm sure that can lower the temperature so much that the outside of the bottle gets a layer of condensation

There is also some kind of pressure buildup caused by the dissolved salts, so I'd not recommend anyone to use glass bottles without venting to store KNO3 concentrate. My bottle full of the concentrate managed to push the stopper out and leak the KNO3 salts over night. I dread to think of the consequences if the stopper didn't pop.

[juggler]

I did propose a method of determining the mass of a rice grain in this thread http://www.aquaticquotient.com/phpbb...c.php?p=137778

Anyway, in the same thread, there's discussion of organic and inorganic PO4. I found that my plants did better with dosing from KH2PO4. You must try it.

Cool huh? KNO3 is endothermic in nature. I always show that "magic trick" to my daughters.

[vinz]

[quote:d60e5b309b="GaspingGurami"]...

There is also some kind of pressure buildup caused by the dissolved salts, so I'd not recommend anyone to use glass bottles without venting to store KNO3 concentrate. My bottle full of the concentrate managed to push the stopper out and leak the KNO3 salts over night. I dread to think of the consequences if the stopper didn't pop. [/quote:d60e5b309b]

This might explain it... cold liquids and gases, when they warm up to room temperature, expands. After you put back the stopper, does is pop out again?

[balacam]

i have always also wanted to know the answer.

i will post this question in the fertilisation forum

[quote:521e8b1001="GaspingGurami"]
Question is, which will give most PO4? Live food or frozen food or dried flake/pellet? And when comparing composition, am I correct to look for types with higher protein composition will give more PO4?

Thanks.[/quote:521e8b1001]

[vinz]

Balacam,

There is no need to start a new thread. We are still well within the topic. I will however, take your suggestion ( for noticing earlier) and move this topic to the fertilisation forum.

[vinz]

Hmmm...

Well, my guess is, most manufactured fish foods are designed to be high on nutrition, including proteins, and low on waste by-products. So, I guess gram for gram, fish food probably has more protein, and hence PO4, then raw foods.

OTOH, how much of that phosphate makes it into the water? Taking uneaten food out of the picture, what happens to the protein/phosphate in the eaten food? How does the body handle excess proteins/phosphate?

Since we're considering PO4 from foods, what about NO3? Manufactured foods will be designed to be low waste... i.e less (usually a lot less) N-compounds compared gram for gram with raw foods. If you're gonna use food to control the PO4 levels, you should consider what it'll do to your NO3 levels.

[GaspingGurami]

[quote:dfb133c2c2="juggler"]I did propose a method of determining the mass of a rice grain in this thread http://www.aquaticquotient.com/phpbb...c.php?p=137778

Anyway, in the same thread, there's discussion of organic and inorganic PO4. I found that my plants did better with dosing from KH2PO4. You must try it.[/quote:dfb133c2c2]

So does it mean that despite a "high" PO4 reading of 2ppm, I should ignore it and continue to dose PO4? What is organic PO4 and what is inorganic PO4. Which is useful to growth?

On a separate matter, this KH2PO4 is powerful stuff. I mix a teaspoon with a cup of water, just to see if it affects pH. At those concentrations, it brought the pH 8 water down to pH 5. Conveniently emptied the contents out the window into a pot of mint on the corridor. 4 days later, all the lower leaves turned from green to yellow to brown GF's mother demanded to know if I've been adding my salty stuff to her plants

[GaspingGurami]

[quote:f84a51f43b="vinz"]Since we're considering PO4 from foods, what about NO3? Manufactured foods will be designed to be low waste... i.e less (usually a lot less) N-compounds compared gram for gram with raw foods. If you're gonna use food to control the PO4 levels, you should consider what it'll do to your NO3 levels.[/quote:f84a51f43b]

Oh no, I MUST dose the KNO3 because I enjoy creating the "endothermic trick", like juggler for the neices to see.

On a serious note, I find that without dosing any ferts and feeding the fishes a mixture of frozen bloodworms, daphnia and mini pellets (from a red box with gold cap and chinese words and a picture of a cardinal tetra in front), lights and CO2, for a 24 hour period, my NO3 drops from 20ppm to lower than 0.5ppm. But the PO4 falls at a slower rate from 2ppm to 1.5ppm. That's why I figure I can escape dosing KH2PO4 by feeding a lot.

Another interesting thing which I noted is that something in my tank is using up copious amounts of iron. I would dose Flourish Iron to make 1ppm, counter check amount of Fe in water with a testkit, and 24 hours later, find Fe down to 0.25ppm again. Not wanting to poison the lifestock, I have now changed my Fe dosing routine to 20drops of LGA to 20litres water daily, and given up on the tedious Fe test. Can anyone comment on this phenomenon?

[juggler]

[quote:28b38eeabb="GaspingGurami"][quote:28b38eeabb="juggler"]I did propose a method of determining the mass of a rice grain in this thread http://www.aquaticquotient.com/phpbb...c.php?p=137778

Anyway, in the same thread, there's discussion of organic and inorganic PO4. I found that my plants did better with dosing from KH2PO4. You must try it.[/quote:28b38eeabb]

So does it mean that despite a "high" PO4 reading of 2ppm, I should ignore it and continue to dose PO4? What is organic PO4 and what is inorganic PO4. Which is useful to growth?[/quote:28b38eeabb]

Inorganic PO4 is more useful, if you read the details in the thread I quoted. I wish to find out more about this as well.

[geoffrey]

[quote:e9c2f652d4="juggler"][quote:e9c2f652d4="GaspingGurami"][quote:e9c2f652d4="juggler"]I did propose a method of determining the mass of a rice grain in this thread http://www.aquaticquotient.com/phpbb...c.php?p=137778

Anyway, in the same thread, there's discussion of organic and inorganic PO4. I found that my plants did better with dosing from KH2PO4. You must try it.[/quote:e9c2f652d4]

So does it mean that despite a "high" PO4 reading of 2ppm, I should ignore it and continue to dose PO4? What is organic PO4 and what is inorganic PO4. Which is useful to growth?[/quote:e9c2f652d4]

Inorganic PO4 is more useful, if you read the details in the thread I quoted. I wish to find out more about this as well.[/quote:e9c2f652d4]

Lawrence,

Yes, inorganic PO4 is better and it should not be associated with cause of algae.

[Plantbrain]

Plants will only use the inorganic PO4, often referred to as DIP. Algae can use either form.

I'd NOT suggest you rely on fish food only, it is far to heavy in N and not enough in PO4.

Use the liquid dosing methods on smaller tanks if you want narrow control.
The 1 tablespoon in 250ml of water works great.

I suggest a rice grain as it's easier than other things to describe.
Although basmati does taste good, I'm still partial to Jasmine personally.

But it's not something you need to be overly concerned with or have close tolernaces with. As long as there's some or excess, you are fine. So whether it's short or long grain, it's not going to matter a whole lot.

Still, it's easy for you to make a stock solution and have very good ranges and know more precisely what you are adding especially to a smaller tank.

Regards,
Tom Barr

[GaspingGurami]

[quote:0cb5b639d0="geoffrey"][quote:0cb5b639d0="juggler"][quote:0cb5b639d0="GaspingGurami"][quote:0cb5b639d0="juggler"]I did propose a method of determining the mass of a rice grain in this thread http://www.aquaticquotient.com/phpbb...c.php?p=137778

Anyway, in the same thread, there's discussion of organic and inorganic PO4. I found that my plants did better with dosing from KH2PO4. You must try it.[/quote:0cb5b639d0]

So does it mean that despite a "high" PO4 reading of 2ppm, I should ignore it and continue to dose PO4? What is organic PO4 and what is inorganic PO4. Which is useful to growth?[/quote:0cb5b639d0]

Inorganic PO4 is more useful, if you read the details in the thread I quoted. I wish to find out more about this as well.[/quote:0cb5b639d0]

Lawrence,

Yes, inorganic PO4 is better and it should not be associated with cause of algae.[/quote:0cb5b639d0]

Ok, Inorganic PO4 is better. So just to be sure that I understood correctly, Inorganic PO4, comes from dissolving KH2PO4 while organic PO4 comes from fish waste. Correct?

Now can anybody help explain why plants can only absorb inorganic PO4 while algae has the ability to absorb both? Curious minds would like to know, thanks in advance.

And to take this inorganic vs organic PO4 discussion further, how does fish food work in a Diana Walstad style setup?

[theodore]

You may want to read this first: http://www.thekrib.com/Plants/Fertil...hosphorus.html

There should be more discussions on this on APD but I'll leave you to look for those yourself.

[juggler]

[quote:0cc792f255="theodore"]You may want to read this first: http://www.thekrib.com/Plants/Fertil...hosphorus.html

There should be more discussions on this on APD but I'll leave you to look for those yourself.[/quote:0cc792f255]

Interesting read. They also mention the there are bacteria that convert the organic PO4 to inorganic PO4. I wonder if such activity is fast enough to produce the inorganic PO4 usuable to plants.

[GaspingGurami]

[quote:c4b5075f="juggler"]Interesting read. They also mention the there are bacteria that convert the organic PO4 to inorganic PO4. I wonder if such activity is fast enough to produce the inorganic PO4 usuable to plants.[/quote:c4b5075f]

So one of the reasons for not changing water in a Diana Walstad style tank is so that the bacteria have time to convert PPo to DPi.

[quote:c4b5075f="Roger Miller"]Oddly, in every case improvements in the cleaning efficiency and decreases in the phosphatase activity had nearly identical effects.[/quote:c4b5075f]

Correct?

Within the same link I read with interest Tom Barr's post on algicial bacteria:

...this algicial behavior with cyano's seems relevant to our tanks and could be a solution even without using antibiotics. Perhaps there are others than can target specific algae. In many tanks, we find algae cannot exist/persist/compete even though the nutrient are available to them. Bacterial actions/presence may be the key.

That post was made over 3 years ago. I'm curious to know if there have been any developments from that. Just imagine... you have bifidus bacteria for your milk, Lactobacillus acidophilus for your drinks and now, Anti BBA and anti BGA bacteria seeds in your bottle of LGA. And on the label, the dosing instructions read: "use as much as desired, and watch your plants take off."

OK, back to work...

[Plantbrain]

"Developments?"
There is no one doing algal research on planted tanks I know of hehe

The non CO2 method allows the time for the DoP => DIP.
the growth rate is slowed way down through CO2 limitation, the other nutrient's uptake rates are also slowed way down.

This allows time for the breakdown to occur at a given rate(feeding fish).
When you add CO2/lots of plants etc, the fish can no longer supply enough nutrients throug organic forms due mainly to NH4, this is what causes algae and why you cannot keep adding fish to supply all the Nitrogen needs of a fish tank with CO2/lots of plants.

Therefore we supplement with inorganic KNO3, KH2PO4 salt etc.
As you amplify such a small little glass box's growth rates, you rely more and more on the inorganic most available forms for good plant growth.

The trick for non CO2 is balancing the fish load/feeding to the plant needs.
Both methods work for the same reason, they both supply enough nutrients for the plants at a given growth rate and both tanks have high plant biomass.

DOP is not an issue for rooted plants, typically there is plenty of DIP in the substrate in natural systems. Algae live in the water column and have no access to this and therefore must make use of any form available to have a better competitive edge in an aquatic system.

Regards,
Tom Barr