I suppose there is some room for debate about why seachem is backed by the best science, but I think if you actually look into how much real science is going into each product you will clearly see my point. Of all the brands of ferts mentioned in the thread so far, seachem is the only one with Chemistry PhD's on their pay roll and they are also the only ones with a full laboratory. After all the company is actually called seachem laboratories. They perform highly controlled studies and have 35 years worth of measurable data. Not a hill I am going to die on, but i don't think you can show me another company that puts as much scientific testing and real data behind their products (i.e. highly controlled and recorded).
I think any fertilizer will "work" in any tank, its more about the skill of the aquarist in knowing how to keep the balance. I have tried mixing the salts, I have tried seachem's line, I've tried easygreen ect... they all grow plants. My point with this thread is about where peoples priority lie? With "estimated index" (EI) as described and created by tom barr, the idea is that you estimate the amount needed and err on the side of too much but do a large (50%) water change at the end of each week to get rid of the excess.
I don't generally change water weekly in my tanks (controversial topic of course) so the estimated index method has me doing more work than all the other methods. Because powdered salts are SSOO concentrated, I find I cannot dial in the exact amount needed to dose the tanks to not have to do a water change. As hobbyists, when we use powdered salts in the small volumes we are making them up in, the standard deviation is very high. If you add a tenth of a gram more one week, or your scale rounds up a little, the amount of nutrients changes drastically requiring you to do the large water changes so you dont build up excess. Because seachem and easy green are made in such large batches, their standard deviation between batches is so small it is negligible. For that reason, i can use seachem very precisely so that I don't have excess nutrients require me to change water all the time. Similarly, the ratios of nutrients are very consistent in easy green so if I find three pumps of easy green plus one mL of seachem phosphate gives me growth without deficiencies or excess I am set and do not have to weigh and mix salts and change lots of water frequently.
Hopefully what I am trying to get across is making sense. EI is obviously the cheapest but I think you can see why it requires the most work for me. That is why my go to has been seachem for a long time, less work. I think if you look at the hobby as a whole, newbies use all in ones, guru's use either individual liquids (like seachem), or powders. I am of course speaking in generalities, but I think the cheap vs easy decision is one that plagues many long time hobbyists.
I personally have found the middle ground in Easy Green (pick any all in one) plus light supplementation as needed
You should try it! Depending on what plants you have you will still have to supplement something but since you are already doing seachem that will be super easy to dial in!
Iron and Phosphate mess all fertilizers up. They have the opposite charge of most of the chemicals in your ferts so they act like a magnet aggregating your fertilizers and precipitating them out of solution making them unavailable for plants to use. That is why people say not to dose macros and micros together, they basically cancel each other out. Also most of the phosphate that goes into your aquarium comes from the fish food, so personally I appreciate the low phosphates.
EDTA is a surfactant. We use it in the scientific field to break up cell membranes, or keep things in solution. That is the purpose of it in easy green. The EDTA is coupled to the maganese and the iron and the other heavy metals with positive charge, to keep them in solution so they do not ruin the whole mixture. That is why they are listed together on the label. Instead of just iron and magansese, it is Iron EDTA, and Maganese EDTA ect. That is why easy green is able to mix the macros and micros, where other brands dont. You will not get edta in your EI powders, and you dont want to add it straight because it will kill a lot of things (BB).
Cory said in a video a couple years back when he released easy green that it matters what order you add things in. You have to mix the Iron and EDTA separately, the maganese and EDTA separately, mix everything else separately, and then mix them together. This very special formulation is what makes easy green easy.
Like I said, I am a career scientist and I use EDTA in my lab often (as well as potassium nitrate, and potasium phosphate ect). This is probably far too in depth for the average aquarist but if anyone is going to appreciate this kind of information, I believe they are on this forum.
All ferts will grow plants when used in balance. It is a question of cost, amount of work, and user experience