Seachem Dosing Schedule

[connorlindeman]

I was inspired by @OliveFish05's post about selling plants and fish and decided to try to sell water sprite and frog bit online. I ordered the plants and I was looking at different fertilizers.

On the seachem website, I found this dosing schedule. I want the plants to grow as fast a possible. Is this way too many additives or is it fine?

https://seachem.com/downloads/charts/Plant-Dose-Chart.pdf

 

[StandbySetting]

Plant growth is determined by lighting, overdosing fertilisers will not make them grow quicker

 

[connorlindeman]

Plant growth is determined by lighting, overdosing fertilisers will not make them grow quicker

yeah, thats true. What is the purpose of fertilizer then?

 

[Byron]

I'll do a brief explanation to cover both aspects.

Aquatic plants require light of sufficient intensity (and spectrum) to drive photosynthesis. The faster growing plants need more intense lighting than slow growers. Duration does not compensate for inadequate or excessive (too much) intensity.

Light must be balanced with nutrients. Without nutrients, regardless of the light, plants cannot grow. Aquatic plants require 17 nutrients; some are macro-nutrients and some micro-nutrients. The level of nutrients must be in balance with the lighting; if not, algae usually takes advantage and either this or the lack of nutrients will kill the plants. The plants that are faster growing need more nutrients in balance with the light than do slow-growers.

Floating plants (Water Sprite, Frogbit) are fast-growers. This is because they get stronger lighting being at the surface. They also have what is termed the aerial advantage, which primarily involves CO2. Carbon is one of the macro-nutrients, and often the first to "run out" in an aquarium. The aerial advantage involves the floating plants' ability to assimilate CO2 from the air as opposed to from the water as occurs with fully submersed plants; for the floating plants, air CO2 can be taken up about four times faster than assimilating CO2 from the water.

That's the carbon dealt with; you will never need to dose carbon with floating plants. The other 16 nutrients may occur within the water, but levels may not be adequate to balance the light. Nutrients can be added by using fertilizers. With fish in the tank the feeding of the fish, plus water changes, replenish some nutrients but it depends upon the fish load just how sufficient these may be.

You want a complete or comprehensive fertilizer. Taking the Seachem Flourish Comprehensive Supplement for the Planted Aquarium since you mention this product, it contains all but three required nutrients. The three missing are carbon (covered above), oxygen and hydrogen; the latter two are obviously always present in water so they can be ignored. Of the remaining 14, all are in FCS but some of the macros (namely calcium, magnesium, nitrogen) are minimal because the manufacturer assumes most water supplies have sufficient calcium and magnesium, and nitrogen is taken up by plants in the form of ammonium (ammonia), which normally is in plenty of supply from fish respiration and decomposition of organics. If there are no fish in this plant tank, nitrogen needs to be added as the ammonia/ammonium will probably be insufficient.

The other nutrients in FCS are in balance according to the requirements of the plants. This product, as the name indicates, is a supplement to nutrients already present, as I described above. The low nitrogen will likely be the limiting factor; I see this in my QT tank for new fish which has floating plants but no fish; the plants are clearly surviving but not thriving, and ammonium is the issue.

 

[Colin_T]

If you don't have fish in the tank, the seachem dosing chart can be used for plants. However, if you have fish in the tank, and you use the dose rates there, you will probably poison the fish.

You need to add enough fertiliser for good plant growth, but not too much so you poison the fish. If you just add some each day (as suggested by seachem), the plants might not use it all up. Each day you add more and the levels build up. Then one day the fish die.

If you want to use plant fertiliser, you should try to monitor the levels of at least some of the ingredients and only add more when needed. Alternatively, add a full dose of fertiliser once or twice a week and do a huge water change before adding another dose. This lets the plants use the nutrients, and the big water change dilutes any remaining nutrients before you add more, so there is less chance of overdosing.

 

[connorlindeman]

If you don't have fish in the tank, the seachem dosing chart can be used for plants. However, if you have fish in the tank, and you use the dose rates there, you will probably poison the fish.

You need to add enough fertiliser for good plant growth, but not too much so you poison the fish. If you just add some each day (as suggested by seachem), the plants might not use it all up. Each day you add more and the levels build up. Then one day the fish die.

If you want to use plant fertiliser, you should try to monitor the levels of at least some of the ingredients and only add more when needed. Alternatively, add a full dose of fertiliser once or twice a week and do a huge water change before adding another dose. This lets the plants use the nutrients, and the bi water change dilutes any remaining nutrients before you add more, so there is less chance of overdosing.

thanks. one of the tanks will have fish and one won't so i appreciate it!

 

[connorlindeman]

I'll do a brief explanation to cover both aspects.

Aquatic plants require light of sufficient intensity (and spectrum) to drive photosynthesis. The faster growing plants need more intense lighting than slow growers. Duration does not compensate for inadequate or excessive (too much) intensity.

Light must be balanced with nutrients. Without nutrients, regardless of the light, plants cannot grow. Aquatic plants require 17 nutrients; some are macro-nutrients and some micro-nutrients. The level of nutrients must be in balance with the lighting; if not, algae usually takes advantage and either this or the lack of nutrients will kill the plants. The plants that are faster growing need more nutrients in balance with the light than do slow-growers.

Floating plants (Water Sprite, Frogbit) are fast-growers. This is because they get stronger lighting being at the surface. They also have what is termed the aerial advantage, which primarily involves CO2. Carbon is one of the macro-nutrients, and often the first to "run out" in an aquarium. The aerial advantage involves the floating plants' ability to assimilate CO2 from the air as opposed to from the water as occurs with fully submersed plants; for the floating plants, air CO2 can be taken up about four times faster than assimilating CO2 from the water.

That's the carbon dealt with; you will never need to dose carbon with floating plants. The other 16 nutrients may occur within the water, but levels may not be adequate to balance the light. Nutrients can be added by using fertilizers. With fish in the tank the feeding of the fish, plus water changes, replenish some nutrients but it depends upon the fish load just how sufficient these may be.

You want a complete or comprehensive fertilizer. Taking the Seachem Flourish Comprehensive Supplement for the Planted Aquarium since you mention this product, it contains all but three required nutrients. The three missing are carbon (covered above), oxygen and hydrogen; the latter two are obviously always present in water so they can be ignored. Of the remaining 14, all are in FCS but some of the macros (namely calcium, magnesium, nitrogen) are minimal because the manufacturer assumes most water supplies have sufficient calcium and magnesium, and nitrogen is taken up by plants in the form of ammonium (ammonia), which normally is in plenty of supply from fish respiration and decomposition of organics. If there are no fish in this plant tank, nitrogen needs to be added as the ammonia/ammonium will probably be insufficient.

The other nutrients in FCS are in balance according to the requirements of the plants. This product, as the name indicates, is a supplement to nutrients already present, as I described above. The low nitrogen will likely be the limiting factor; I see this in my QT tank for new fish which has floating plants but no fish; the plants are clearly surviving but not thriving, and ammonium is the issue.

thanks for the super detailed reply! It really helped me understand better