Schmidty

I do not have plants in my tank yet. I probably won't be able to get them for a while, due to my low-light situation (stupid aquarium kits with inadequate lighting....grumble grumble )
However, if in the future I am able to upgrade my lighting, there is another concern I have. Right now I have a HOB filter that uses activated carbon. Here is an example of my cartridge. Do I have to eliminate the use of activated carbon to grow plants? Is there any way to get filter cartridges for this type of filter without the activated carbon? Will I have to replace my filter in order to grow plants?
Thanks for any information you can provide!
--Schmidty

jsalemi

Carbon will filter out some of the nutrients the plants use, but you can counter that by using root tabs that dissolve and put the nutrients back where the plants can use them.

You can also get two-part 'bio-max' style filters like these bio 3-- the carbon is in a separate pack from the sponge, and you can just use the sponge (or two sponges) and only put in the carbon when you need it to clean the water.

Chief_waterchanger

There are 3 types of filtration:

Biological, Mechanical, Chemical.

Biological filtration:

Is the converting of toxic materials (urea) into a less toxic form (ammonia). Urea is converted to ammonia, ammonia is converted to nitrates, nitrates are converted to nitrites. This is done by bacteria in your fish tank. Bacteria grows on every surface. It is the reason you put porous materials such as filter floss and sponges into your filters. This increases the surface area the bacteria have to grow on.

Mechanical filtration:

Is a physical removal of waste products (fecal matter/dead plant material/etc) from the tank. This is done by your filter floss and sponges in your filtration systems.

Chemical filtration:

Is the chemical removal of waste or medications from the aquarium. This is usually achieved by using activated carbon. Activated carbon removes both organic molecules and metallic ions from the water. Activated carbon is filled up (at its saturation point) in a very short time. This is measured in hours at best. Saturation point is normally reached in an hour or two at the most. It falls on the later end of the spectrum in colder temperatures.

So to answer your questions after all of that:

Activated carbon will remove elements that plants need from the water, but unless you dose fertilizers right after you've changed your activated carbon, it should not make any difference.

We use replacement sponges made by aquaclear instead of cartridges. We also use filter floss. Filter floss is the lesser of the two because you lose your bacteria when you change it.

So no, you do not have to get rid of that filter, and as long as you do not dose your fertilizers the same day as you replace the activated carbon you should be fine.

Hope that helps.

TheEssigs

There was a decent article, not to long ago in Aquarium International, about carbon filters and plants... and the jist and the conclusion of that article is this...

Activated carbon does not effectively filter metals and salts. It will not remove iron, magnesium, phosphates or potassium or any other trace element that plants like. Activated carbon will not harm your plants neither. So, it will do an effective job with many medications and many dissolved organic compounds that build up in the aquarium... so it does have some benefits in a planted aquarium.

I think the confusion came from when the hobby also used charchoal as a filter medium and thats where the blame lies.

OK, well, I hope that helped.

catersun

Umm... must be a typo... nitrite is turned in to nitrate

sjlchgo

I have plants in my aquarium and when I was using the carbon my plants were suffering. I have since removed the carbon and put in the sponges. This does cause me to have to change the water more often but for my plants, it's worth it! The are growing like crazy now. You have to choose between the lessor of the two evils. Also, if you have plants.....DO NOT USE SALT! Plants hate salt.

pistorta

I use a media called Renew which is an activated carbon substitute for planted aquariums.

jsalemi

Hmm, hadn't heard of Renew, but I found it over on DFS. Seachem is doing some interesting stuff these days. I'll have to try it out.

sjlchgo

Renew huh Gonna have to give that a try.