Best fertilizer, and I had tried lots of others before. For over a year now: perfect plant growth, no deficiency symptoms and no algae. Highly recommend.

Have been using this fertilizer for 2 weeks now in combination with the Aqua Rebell Mikro Basic Eisen. Since then a clear improvement in plant growth and healthy plants.
I started with half of the recommended dosage at first, just as the Estimative Index method prescribes.

Unlike other reviewers, I can confirm that you can measure nitrate, phosphate and potassium very well and easily with drop tests, and you should do so (!).

Here's a usable NPK fertilizer, also with a usable value for money.

Pros:
- simple and sufficient on its own for the first weeks
- Potassium content is chosen low enough here (thanks!).
- Supplemented with an iron fertilizer you also get by well with K (Fe has to be dosed at a different time).

Cons:
- Concentration of the ingredients is not very high (which makes the price look cheaper than it is)
- Nitrate-phosphate ratio not perfect for me

As with other reviewers, in my case the phosphate level kept rising while nitrate is completely consumed by the plants. So nitrate has to be added in the long run so the plants can use up the P, otherwise P keeps rising. High P levels lead first to strong algae growth and in the long run to a weakening of the immune system of the aquarium inhabitants. As soon as you fertilize, testing is mandatory ;)

In summary, as you know from AQR, a good product where you can be sure that what's on the label is inside and nothing else. Price-wise it can be done cheaper because other fertilizers have a higher concentration. In the long run, depending on substrate, stocking etc., the fertilizer is more of a P fertilizer with an N component that you have to supplement. For a fresh tank the fertilizer is great because it's absolutely uncomplicated to handle. You can follow the recommendations on the bottle (combined with small water changes) without worry for a few weeks, after that you need tests as always.

I've been involved in the aquarium hobby for many years. About 5 years ago I came across the fertilizers from Aqua Rebell. Since then my plants have been growing and thriving like never before. I should also mention that I'm not always that precise about fertilizing, I simply forget. My plants grow so well that I can cover pretty much all the side costs of my hobby with the proceeds from selling them.
My 100% recommendation.

I run a 37-liter aquascape with a lot of plant mass. Because of very high lighting and CO2 supply I had extremely low nutrient levels, which led to deficiency symptoms. Since the Estimative Index, no longer an issue! The plants are bursting with vibrant color and growing like crazy!
However, you guys should be careful with the dosing so your animals don't suffer!

I would buy it if only the packaging didn't look like a scouring cleanser from Aldi. You guys can do better than that.

Very good fertilizer at a very good price.
Hardly any algae left thanks to this product.
Highly recommended.
Delivery was first-rate again

I can't really rate it myself, I ordered this fertilizer to give it as a gift, it arrived great as a gift, and so far I've only gotten positive feedback from the recipient

Simply one of the best fertilizers on the market... By that I mean the entire Aqua Rebell range, keep it up guys

Easy to dose, together with the iron fertilizer you can hardly do anything wrong even as a beginner, and our plants thank us for it

Don't be afraid of EI. You don't always have to dose it exactly. You can also take half and feel your way up and you're still better off than with no NPK at all. E.g. out of fear of getting algae or harming the animals. Thanks for making it available :-) In stores around here you can't find an N or NPK fertilizer anywhere, not anywhere. Even Dennerle Boost is no longer available :-( All philistines.

Truly beautiful aquatic plants, in great colors and magnificent growth. I additionally use Spezial N. With the Mikro Basic Eisenvolldünger a well-rounded thing for me. The perfect fertilizing system that has no equal! I'll also get the Spezial FLOWGROW and see what happens. 6.****** from me. P.S.: Should be on offer in every pet store ( A MUST )

Strong fertilizer, supplies all kind of macro nutrients.very easy to dose with Aqua Rebell Dosing pump 1 ml.I have no algae issues.

I've been using the Estimative Index fertilizer as a base for a while, while also dosing additional N.
I think the product is good and inexpensive.

After hours of researching in the Flowgrow forum, I decided against ADA and for Aquarebell for my soil tank.
Then the question was: which fertilizer.
After a phone consultation with Marcel at Aquasabi I decided on the combination EI 1 ml per 50 L, Flowgrow 1 ml per 50 L and Spezial N 1 ml per 50 L (I've since increased it slightly). 50 % water change (KH 5/ GH9) weekly and strong LED lighting.
What can I say, plants are growing, practically no algae.
Excellent.

The fertilizer does what it's supposed to do. Depending on the tank, nitrate has to be supplemented, but that doesn't say anything bad about the fertilizer.

What more is there to write?
For me simply one of the best fertilizers on the market, also in terms of price.
So: a clear recommendation from me.
Delivery and packaging: fast and great, as always with Aquasabi.
Thanks for that!

. . . for years without problems. What is there to complain about anyway, it grows:) No problems . .

What is there to write, it's been working excellently for ages. I'll keep buying it. . . . . .

With the Estimative Index a good macronutrient supply is possible and the plants thank you with healthy growth. Regular water changes are still recommended here, though.

Very good, nothing more to say, you can practically watch the plants grow ;) Thumbs up

I've been using this along with Mikro Spezial and have been very impressed with the results, plants love it and so do I. Highly recommended !

trouble-free fertilizer in my display tank with 45 lm/l, 25 mg/l CO² and high nitrate and phosphate levels, substrate garnet sand and black matte quartz gravel. Works well with the Mikro iron fertilizer; no problems so far.

Who wants to measure water parameters forever?
Especially the NO3 and PO4 tests are quite laborious, and K is practically not measurable with hobby aquarium tests.

That pushes the otherwise common macro fertilization methods, where you basically have to know your NPK values, into the realm of theory and in the end achieve the opposite of what they're supposed to achieve, namely good plant growth without algae.

Provided you have decent light, CO2 and a sensible micro fertilizer (here AR Mikro Basic Eisen-Volldünger), with this fertilizer and the “ballpark” macro fertilization you create the best conditions for excellent plant growth.
Even in a tank stocked with fish (sensibly, not overstocked) a macro deficiency can occur with good light and 20-30 mg/l CO2. Usually the problem is less the NO3, which is often already present in tap water and is also introduced through dry food and filtration, but rather the K and the PO4. Frozen food usually contains quite a lot of PO4, which you should keep in mind, but it's only fed about 1-2 times a week here. On the other hand, PO4 is almost never present in tap water.
I myself use only remineralized RO water, which is free of macros anyway. K is also in the micro fertilizer, but with lush growth it's not enough either. Unfortunately, as said, not measurable with hobby aquarium tests, so you should keep an eye out for possible deficiency symptoms.

Somewhat less NO3 in the fertilizer would not be bad for tanks with fish, but with halfway regular water changes it works fine like this, too.
Excellent fertilizer, but only for CO2-fertilized tanks with decent light.

A really good fertilizer that is highly recommended together with the Estimative Index system. Since I started using it I hardly have any algae anymore and the plant growth is fantastic!

For a long time I had problems with everything and stunted growth. Since I switched my tank to aquasabi and optimized my fertilizing schedule, everything grows and thrives much better.

Ever since I switched from regular NPK and complete iron fertilizer to EI, I've finally gotten rid of my growth problems. The mix of fast- and slow-growing plants shows you very quickly which direction things are heading. Since then I haven't had to replace any plants. On the contrary.
Highly recommended!!!

I'm always very satisfied with the fertilizer, I use it as NPK. Delivery is always very fast, which I also really appreciate about you guys. Thanks Aqua Rebell, you're the best!!!!

Ever since I started using the EI fertilizer, the tank (lots of light & CO2) is positively exploding with lush green, healthy plants - EXCELLENT!

Stable and nutritious (for the plants), my expectations were met, an absolutely highly recommended product.
Magnificent plant growth that doesn't explode but stays steady.

It works excellently! Everything grows and thrives. From now on only Aquarebell!

Great, simply fantastic, always happy to order again. Algae are almost gone.

Properly dosed, it's a knockout in combination with Flowgrow!!

Very fast delivery

Very fast shipping

the last delivery even included a free aquatic plant

Fast shipping. Delivery was excellent and I'd recommend the product, too.

AR fertilizers are the best ready-to-use fertilizers!

Great results, easy dosing, highly recommended.

Satisfied as always!

High-quality products, VERY fast shipping, Aquasabi excellent as always.
I'll definitely order here again.
Many thanks, keep it up.

Best wishes from the Hanseatic city of Stralsund

Good value for money. I only use this NPK fertilizer for my tanks now.

The Aqua Rebell fertilizers are great and shipping was super fast!

very fast delivery as always

A good fertilizer, but I find the Makro Basic better for my aquarium.

Good fertilizer. When matched with all the other components, very very good!

Unsuitable for my purposes, otherwise good if you don't want to use special fertilizers

The product is sensational at the right dosage and in combination with other AquaRebell products.
It's equally suited for beginners and advanced aquarists.

Great fertilizer. Would buy again

Great plant growth. Had problems with plant growth the whole time. Since I started using this fertilizer
the plants have kicked into high gear. Really satisfied with the fertilizer.

Best regards
Alex S.

Very good value for money, great result with the plants... THANKS A LOT FOR THAT

Very good plant growth!

Simply fantastic, saw success quickly, super fast shipping

Fantastic fertilizer. Highly recommended. Great results. And the service was very fast!!

Hi,
so far I've tried a few fertilizers and I've stuck with the combination of AR Makro Basic EI plus AR Mikro Basic Flowgrow plus Easy Carbo. Seems to work, and the tank is slowly heading in the direction I want, meaning the plants are photosynthesizing like they're getting paid for it, and the damn green algae are slowly receding.
That the delivery speed here easily puts Amazon in the shade is something everybody writes anyway. Clear recommendation and best regards from Berlin.

What more is there to say, everything as always. Great products at a fair price, super fast processing and all of it first-rate packed. Simply perfect.

I can't recommend this fertilizer highly enough, the value for money is just perfect

Great fertilizer! Top-notch quality from Aquasabi, as always. Delivered fast, very well packed,

Really excellent fertilizer, for people who don't want the hassle of individual fertilizers and still want to fertilize in a targeted way. Highly recommend it

I'm very happy with this fertilizer. My plants are growing very well.

Very happy - it's a great fertilizer -
just a few days after using it, the
effect was visible. I barely
recognized my plants.

Really awesome, this macro fertilizer.
Targeted fertilizing without much effort!

Everything is very good. This stuff is making my little underwater world green up. Respect for that.

Great product! After reading up on EI extensively at Flowgrow, I wanted to try it without having to handle chemicals myself. This fertilizer is the solution. Combined with the Mikro Spezial Flowgrow, my plants assimilate like crazy and the algae I've been fighting forever are disappearing!
The authors of the many aquarium books should start revising the myths about the evil NO3 and PO4.
Thank you so much, Tobi, I was also very happy about the free extra!!!

I recently ordered this fertilizer together with the Mikro Basic - Eisenvolldünger - 500 ml here at Aquasabi. The whole ordering process and payment went very smoothly. I was kept informed about my current order at all times. The delivery arrived within three days. Great...

Now on to the fertilizer. Here, too, you should read up on the "Estimative Index" beforehand. A good place to start is the Flowgrow forum. You really can't do much wrong with this fertilizer, especially since detailed instructions are provided here in the shop as well as on the back of the bottle. (The print could be a little bigger).

I started fertilizing below the minimum recommended dose, since I have many plants in the tank but only lighting of 2 x T8 tubes, and that with a tank height of 50cm. I get along very well with the dose I chose. I have to say, a great product. I always had small beard algae, which have now disappeared completely. The plants grow faster and have intense coloration.

I'd give this an absolute buying recommendation.

It's a dream! The easiest way to try out this fairly foolproof fertilizing concept. And: don't be too timid with the dose, that's the whole point of EI after all!

This fertilizer is simply top class. Everything grows brilliantly and the plants show truly breathtaking colors.

All great products.
The free extra is a great idea, too.

Very good product (significantly better plant growth). Highly recommend.

So far we have had very good experiences with this fertilizer.

Very good fertilizer! It allows me to fertilize generously without fear of green algae, since it contains no
ammonium. Very fast shipping.

Since I started using the Makro Basic EI, all my plants grow much better and are lush green again.
In addition, the annoying aerial roots on the stem plants no longer appear and even the algae are in retreat.
But I'm also very happy with the super fast delivery. Always happy to order again.

Regards, Alex

With the Glosso I noticed the improvement very quickly. However, you should be careful to put less into the tank at first and keep an eye on the values. If too much is added, algae can form quickly. So less is sometimes more.

Easy to dose, plants develop as desired.

Very happy. My plants in the South America tank are now growing even better. Now I can also detect some NO3 and PO4 in the tank water by measurement.

Very good product!

Great product, easy to dose!
A+

Super, six stars for this product

Great, plants are growing like they used to again.

For me an excellent complement to Profito for supplying plants with the necessary macros.
The plants say thanks with strong growth.

Flawless, it clearly helped me with my algae problems
The plants grow better and they crowd out the algae. After just one week there was clearly visible plant growth.
Algae after approx. 2 weeks ? = none

This product is highly recommended!! I used to use PROFITO, which didn't convince me because the algae problem was still there. But since I've been using Makro Basic Estimative Index together with Makro Basic all-in-one iron fertilizer, the algae problem has been solved and plant growth has improved many times over! They grow like crazy!! But keep in mind that this product can only deliver such results in combination with enough CO2 and light!!!

Hello, I'm very happy with the Makro Basic EI fertilizer. I use it together with the Micro Basic Eisenvolldünger. My plants are all thriving.

In my view a very good product, with the help of which I got my plants growing well. But you should definitely adjust the dosage to your needs and not forget the regular partial water changes, then it'll work out with the neighbor, er, the plants.

I'm very enthusiastic about the Estimative Index fertilizer. After a short time the first successes showed. (despite overfertilizing :-) ) For smaller tanks and people who don't feel like measuring water parameters, a really great fertilizer.

This fertilizer convinced me!
After trying many things and never being quite satisfied with the results, this is finally a system that is user-friendly and good.
I dose it more sparingly than stated, because I have a high stocking density and only 152 W / 300 l .
Combined with Micro Basic, it finally helped me get nice plant growth after an algae plague and stagnant growth. The coloration of the tiger lotus and especially of the E. - ozelot are now shown off beautifully. The water parameters stay fine with a weekly water change of 50 %.
I'm very happy.

Convincing product with a practical dosing aid. Thanks to this product I got my green algae plague under control and reduced the algae to small colonies. The reason for this was an undersupply of the plants with nitrate and phosphate. I can definitely recommend this product.

Regards

Hello,

I'm 100% convinced by this fertilizer.
Plants that didn't grow for me before are growing now.
But usually only once you've found your own fertilizer dosage.
This is described in the product description, after all.

Big praise for the fast delivery, too! EVERYTHING WAS PERFECT

Hello,

Makro Basic EI was an attempt for me to combine P and N in one fertilizer. Unfortunately the whole thing only works to a limited extent, i.e. while N is used up in no time, P accumulates in my tanks with regular addition of the fertilizer. I now use the fertilizer as a P fertilizer and have to fertilize N additionally.

I had already suspected that it would be difficult to combine P and N in one fertilizer. The consumption of these two substances is very individual. Therefore I will use single components again in the future.

Best regards,

Michael Niesar

Hi,
I can highly recommend the EI Macro fertilizer from Aqua Rebell, it made my Iwagumi work and my next project is also developing wonderfully. Everything grows like crazy, with strong light, enough CO2 and micro fertilizer it'll work for you guys too ;-)

Hello everyone,
I've had very good experiences with the EI from Aquasabi.de. I run a high-light tank with well over 1 watt per liter, where the plants are clearly the focus. After initially massive thread algae problems, the tank visibly improved after switching to EI. Today I only have remnants of the algae plague. You should give yourself a push, break the traditional rules and dare to add large amounts of macronutrients, too (because that's exactly what you do with EI). I can only report positive things.

Best regards
Axel