Non Fertilized 110 Gallon

[cuda]

I have a 110 gallon heavily planted tank, with a fairly heavy fish load that is about six months old. I have always fertilized in the past lightly, but after an algae outbreak about three months ago I wanted to see what would happen with no fertilizer, and have been amazed. The tank has CO2 injection but has never skipped a beat as far as growth or color/deficiencies. I believe there is a happy medium between fish waste/fertilizer, and plant requirements. I guess time will tell, but with over 16 varieties of plants and not one problem ( I still have to trim out about a gallon of plant material weekly) things are looking good. My substrate is locally collected stream pebbles and sand nothing store bought or mineralized. There are about 120 inches of fish in the tank as well (tetras,loaches,cories,plecos,kribs,shrimp,ottos,siamese algae eaters,barbs) and have not lost one fish. I will continue to go without fertilizers as long as things are healthy. I do a 25% water change weekly. Has anyone ever done this with success long term?

 

[snazy]

As long as the balance doesn't change, including the type of fish food/variety as each one contains different eventual "ferts", and if the tank has been going for 3 months on that diet with no issues since stopping the extra ferts, then it should be good I would think... It seems the hard problem is reaching the balance, but once you get there the details making up the whole picture can be totally different from tank to tank. There's no absolute rule, just quidance that we all follow, sometimes blindly and unnecessary.
I had to stop ferts and CO2 in a small shrimp tank as I thought something wasn't agreeing with the shrimp in it,one died and one got sick. That was about only 4 weeks ago, the rest of the shrimp are fine since, shrimplets growing. Plant wise it's probably still early to tell if all of them will last but at the moment they are growing like they haven't noticed any difference since stopping the ferts and CO2, which is strange. It's a heavily stocked tank at the moment too(overfiltered as well). It has a big bunch of growing cory fry and a bunch of shrimp, getting fed several times daily.

 

[Ps3Steveo]

All I'd say is to keep an eye on things as you may have a nice build up of phosphates and nitrates along with other fertilising nutrients, the CO2 if injected at a high rate may make the plants use up those nutrients quickly or slowly depending on how much is kept in the water. It may last a long time if some of the CO2 gasses off but may not last long if its all kept in the water column. Just keep an eye for algae and plant deficiencies.

 

[cuda]

Thanks for the reply, I will keep up this "experiment" until I see a need for fertilizer. Im sure eventually there will be a need for some minor elements, probably iron. Just curious if anyone has had success long term?