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How much Potassium Phosphate (KH2PO4) for 300 litre heavy planted tank?

And no one seems to bother.
I would like scientific evidence, sadly ony few people can/wil do that in the environment of an aquarium. And even then some data are skewed to put a product./firm in a positive light.
Basic scientific double blind studies in aquaria are far and few between. Most data we have are derived from whole other studies like aquaculture/ non-aquatic plant studies, or simple comparative studies (a few plants under the same environment with one seemingly different parameter)
 
If plants only use up 0.5 ppm of PO4 then we shall investigate, but for this there has to be some proof. Even so one thing is the comsumption and another different one is the levels at which plants start doing better.
My recent tests suggest this, but I have to do other tests to verify it. After that I publish my results and methods. Also I consult this matter with some scientists to be sure I do it correctly. Although these are not any precise scientific analyses, I believe they can shed some light on nutrient uptake in planted tanks. I wish I could do some laboratory measurements of photosynthesis rate at different levels of different nutrients with different kind of plants, but it seems like there are just a few facilities doing these kind of analyses, and the cost would be super high (like €160 per hour!). As I know even Tropica don't want to invest into it. But still there are other methods to find out some raw numbers for our tanks. And these methods are maybe of better value for us then the precise scientific numbers for compensation or saturation points.
Ada tanks have easy explanations. They have just the light needed to pearl. They have a substrate which is leaching nutrients continiously. Co2 as bubbles in a tank have been shown to be very effective.
I don't think that your kind of explanation explains anything. Each plant begins to pearl at different conditions. The plants pearl when there is too much oxygen present in their inner atmosphere, and the inner gas concentration (O2 + N2 + CO2 + CH4) begins to be higher then the outer concentration of dissolved gas in water. True aquatic plants which can utilize HCO3 can pearl much easier then plants which are able to use only free CO2. So pearling depends to great extent on the plant species you have in your tank. Some kind of plants grow very slowly and produce little oxygen so its very hard to see them pearl at all. Besides this, ADA substrate (as I already said) has nearly no P content, so it may leach N (whether in NH4 or NO3 form) but it has too little PO4 to support any substantial plant growth by itself. Also, please, can you give me some link to materials which prove CO2 bubbles are more effective then dissolved free CO2? I doubt it a lot, but you probably have some better information if you claim this. Don't take it harsh. I just try to discuss it, and if you say it's easy explanation, then you should have no problem to give me some proofs (when you yourself want me to do the same).
 
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And even then some data are skewed to put a product./firm in a positive light
I am not going to defend any brand but I have to admit that it is not easy at all explaining to a customer all this in a 5x3 cm label... even in a website. IME only a few hobbyists are really interested in discussing about this, searching for other information sources, asking for advice when they do not understand something...We all have seen people at our LFS asking interesting questions and obtaining trustful advice, but I've seen also people that just want to buy miracles and that are happy to pay miracles.

Jordi
 
I don't think that your kind of explanation explains anything. Each plant begins to pearl at different conditions. The plants pearl when there is too much oxygen present in their inner atmosphere, and the inner gas concentration (O2 + N2 + CO2 + CH4) begins to be higher then the outer concentration of dissolved gas in water. True aquatic plants which can utilize HCO3 can pearl much easier then plants which are able to use only free CO2. So pearling depends to great extent on the plant species you have in your tank. Some kind of plants grow very slowly and produce little oxygen so its very hard to see them pearl at all. Besides this, ADA substrate (as I already said) has nearly no P content, so it may leach N (whether in NH4 or NO3 form) but it has too little PO4 to support any substantial plant growth by itself. Also, please, can you give me some link to materials which prove CO2 bubbles are more effective then dissolved free CO2? I doubt it a lot, but you probably have some better information if you claim this. Don't take it harsh. I just try to discuss it, and if you say it's easy explanation, then you should have no problem to give me some proofs (when you yourself want me to do the same).

I dont have scientific proof for this.
I can only speak for the hundreds of tanks that are are done with diffusers and which most probably dont have a 1 ph degree change. Im speaking of ADA, Tropica, Most famous aquascapers except maybe Tom Barr and a few others.
I am also speaking for what Ive seen in my tanks which is no scientific data of course.

But in the end ADA tanks arent tanks made by the gods (you could argua Amano is one I suppose). They just use simple technology. You dont need to back up everything with an experiment, somethings are explainable just by watching.

Also I dont understand the concentrations you have given for the soil. They are given in different units and I cant really tell what they represent since Im unsure how you did the experiment etc. So we cant argue about those results, we need more info.
 
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I can only speak for the hundreds of tanks that are are done with diffusers and which most probably dont have a 1 ph degree change. Im speaking of ADA, Tropica, Most famous aquascapers except maybe Tom Barr and a few others
Maybe I am misunderstanding this sentence... but do you mean that tanks using diffusers including ADA, Tropica, Viktor Lantos, etc.do not reach this 1 pH fall (except Tom Barr and a few others thay can achieve)? Wow... I really doubt it.

Jordi

P.S. I guess no one thinks Amano is a god (nor Tom Barr). They just know very well what they do (as always it is as simple as assuming that there are different techniques/approaches that work)
 
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Maybe I am misunderstanding this sentence... but do you mean that tanks using diffusers including ADA, Tropica, etc. ones do not reach this 1 pH fall (except Tom Barr and a few others)? Wow... I really doubt it.
Yes this is what I mean. I once read a post on thebarrreport where he said Ammano normally aims for 18 ppm CO2 or so.
I dont know why you seem to think this is not possible or recommended since CO2 has to be in relation with the light. There can be as many CO2 levels as light intensities.

You can have a look at James Finley tanks. They are tanks with just a fine stream line of CO2 coming from a CO2 diffuser. Do you think you can reach 30 ppm CO2 this way. And hes got gorgeous tanks with carpets and all.
 
When I say you dont need scientific evidence for everything what I mean is for finding out things or proving things to yourself. For most things in life there are no scientific studies, but you can certainly see a trend or tendency with your own eyes. Of course this trends are nothing solid and you have to be openminded for whatever comes up. I think this is as useful for a hobbiest as scientific studies.
 
P.S. I guess no one thinks Amano is a god (nor Tom Barr). They just know very well what they do (as always it is as simple as assuming that there are different techniques/approaches that work)
I was really just kidding here:). I dont have a statue of Amano to pray to in my room either (I promise).
 
Do you think you can reach 30 ppm CO2 this way.
Yes, I do believe that a 1 ph drop is not a unique skill reserved to Tom Barr and that thousand of hobbyists in this world achieve it with normal diffusers.

They are tanks with just a fine stream line of CO2 coming from a CO2 diffuser
Seeing a fine stream of bubles don't mean a thing, there are many parameters that may influence CO2 dissolution and distribution in a planted tank.

I once read a post on thebarrreport where he said Ammano normally aims for 18 ppm CO2 or so.
Sorry, but this doesn't sound as a very solid evidence of what Amano does.

Jordi
 
(Jose, I really appreciate these exchanges we are having but I fear with are hijacking the thread, don't you think :))
 
Do you think you can reach 30 ppm CO2 this way.
Yes, I do believe that a 1 ph drop is not a unique skill reserved to Tom Barr and that thousand of hobbyists in this world achieve it with normal diffusers.
Jose said: ↑
They are tanks with just a fine stream line of CO2 coming from a CO2 diffuser
Seeing a fine stream of bubles don't mean a thing, there are many parameters that may influence CO2 dissolution and distribution in a planted tank.
Jose said: ↑
I once read a post on thebarrreport where he said Ammano normally aims for 18 ppm CO2 or so.
Sorry, but this doesn't sound as a very solid evidence of what Amano does.
Jordi

Ok. Its up to you to try it, or maybe you dont need to. Any way its a very simple and easy experiment. Actually Tom Barr has done it. Measuring dissolved oxygen in the water with a diffuser or atomizer. He saw great results. People think things havent been done but many have.
 
Does anyone kno whats wrong with thebarrreport.com¿?. I cant access most of the free info there was before? Has it been closed down or something similar?¿?¿:(
 
I've been reading a lot of articles and sending emails to Mass aquariums, Barrreport, Dennis Wong etc. and I still get confused. I'm dosing per week 15.25 N, 14.76 K, 4.1 PO4, 3.68 Mg, 0.62 Fe from csm+b in a 40 gal tank with med to high light. CO2 injection thru a diy reactor.
What I wonder is if I increase the PO4 that would increase the K as well. Does that matter?
That's why I wish I knew if my numbers were at good levels?

I saw an article that says the P and K should be higher than the N to get more Red in the plants, is this correct?
 
Hi all,
Others will disagree, but I'd be surprised if any-one who adds PO4 regularly has plants which are phosphorus deficient. Even though phosphorus is one of the macro-nutrients, plants need only about 1/10 as much P as they do nitrogen (N) or potassium (K).

cheers Darrel
Hi Darrell, You can have this issue when rocks and sometimes the substrate seems to adsorb the PO4 in the initial stages of tank establishment. Later you only need small amounts as you state.

Would adding CaSO4 and KH2PO4 together cause the precipitation?
 
I
I saw an article that says the P and K should be higher than the N to get more Red in the plants, is this correct?
This is another big topic and there is a thread about red plants in this forum. Have a look at that one.
 
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