When to dose ferts?

[**sarahp**]

As the title says really - when is the best time to dose ferts? I use flourish comprehensive and wondered if it would react to my water condtioner, I use Easy-life filter medium.

At the moment I wait 24 hours after a water change - done weekly at a rate of 60-70% - but wondered if tht was ok?

 

[Byron]

I dose Flourish Comprehensive the day following the water change. I started doing this a few years ago after corresponding with Seachem who advised that some of the minerals in this fertilizer could be "removed" by water conditioners that detoxify heavy metals, and they recommend waiting 24-36 hours. There is another reason to do this, I'll come back to in a moment.

"Heavy metals" include copper, iron, zinc, manganese and maybe others that are also necessary plant nutrients. There is no point in adding these, then immediately making them inactive. So dosing Flourish Comprehensive the day following the use of your water conditioner (which does detoxify heavy metals, I looked it up) seems wise. Most conditioners are limited in their effective time periods.

The other reason I would recommend a day's delay is that fish will be calmer. Water changes may stress fish a bit, depending how "extensive" your work in the tank is, but there will be a beneficial change in water chemistry to some degree. Any substance added to the tank water will get inside the fish naturally; water passes into each cell via osmosis, and from there it enters the bloodstream and internal organs. This also occurs in the gills. Conditioners are necessary to dechlorinate, but they still get inside the fish. So will plant additives. Keeping these to a minimum at any one time is better. So for this reason alone I wait a day.

That brings me to the volume. Any substance added to the tank should be minimal--remember they all get inside the fish. There is no purpose served in dosing more than is needed, of any substance, be it conditioner or plant fertilizer. I used to use twice weekly doses of Flourish Comprehensive until a microbiologist pointed out the dangers of all this stuff inside the fish, and I cut back. After several weeks of no fertilizer and slowly working up over several weeks between increases, I got to my present regime which is working fine. I dose just under the recommended weekly dose, once, and no more. My algae problem in a couple tanks disappeared as well. Each tank is different, and I also use Flourish Tabs for my larger swords; these make quite a difference, and allow me to cut back on liquid. And the tabs do not get into the water column, so they do not get inside fish. So there is double benefit to using less. I am also careful not to overdose conditioner; the manufacturer's claims that using more than needed is "safe for fish" is nonsense.

Hope this helps.

Byron.

 

[StevenF]

The main advantage of dry fertilizers is that you don't pay for the shipping cost associated with shipping water (which is heavy). Also mold won't grow in a container of dry fertilizer. It however can grow in Flourish. One disadvantage of dry fertilizers is they are often mad from fertilizers made for terrestrial plants. Not aquatic plants. As a result they often don't have calcium sulfur, chlorine, nickel and cobalt.. And sometimes they may contain ingredients that are potentially toxic to fish or shrimp. . Flourish comprehensive and Brightwell Aquatics florinmulti liquid fertilziers are much better than most other fertilizers because they have all of the nutrients that are often missing from other fertilizers.

My advice is that if you are getting good results with your current fertilizer there is no advantage to changing to dry. So stay with what works for you.

 

[**sarahp**]

Thanks Byron, that's very helpful.

I only use the bare minimum of either fert or water conditioner having read several of your posts about whatever we put in the water gets into the fish. Seems obvious when you say it but I hadn't ever thought of it before. So now I only dose conditioner for the amount of water changed. I do use root tabs as well so use less liquid fert.

It's good to know I was right to wait 24 hours so that my conditioner didn't negate my fertiliser - thanks for the help

 

[AbbeysDad]

I agree that when using conditioners, waiting 24-48 hours makes good sense to better ensure that the fert isn't being made less effective by some conditioners. (e.g. Prime (and others) that bind heavy metals as Byron pointed out).
I also agree in finding the sweet spot that allows you to use minimal fertilizer while still feeding your plants.
It's almost 'funny' that so many hobbyists overdo fertilizers in order to push plants for maximum growth. They seem to ignore the organics involved.
Do you remember (as I do) in our youth when we learned that when the Pilgrims came to America, the American Indians taught them about planting a fish with their Maze (corn), The fish decomposes and provides food for the heavy (corn) feeder. So FISH FOOD (good foods are mostly fish products) and fish waste will fertilize the plants. We just need a little fertilizer to balance what's not already in the water. Overkill is not only wasteful, but likely not good for the fish. The true advantage of the planted aquarium is that the plants help purify the water, making a healthier environment for the fish...unless we negate the benefit by adding excess chemicals!
-Mike