It been several years since I've been around on the forums, but my plant growth has faded into the realm of terrible and I'm wondering if the age of my Fluorite may be playing a role.

The tank is about six years old and grew easier plants such as val's, crypts well although I was always disappointed in my inability to grow good groundcover. I chalked it up to very inconsistent dosing and relatively hard water. I do automated 15 pcnt daily water changes, generally run CO2 and have 216 watts of geismann light in an 83 gallon tank.

Now, I've given up on more difficult plants and can't even get my old standard o Val's and crypt's to grow well. Giant Val is red but curled or wrinkly and just isn't robust for the small amount it's growing. It's dividing well as Val's usually do but it's jus not getting enough nutrients. This is despite using root tabs and such.

Obviously my water column fertilization needs to improve, but my question is, will fertilization take care of it, or has my substrate lost it ability to grow things?

Hi, your fertilization, even in water column, should take care of it. Flourite has good CEC and CEC should stay good even with time, it is supposed to last very long.

Mine is 4 years old.

Check the fluorescent tubes, are they old? Double check the ferts routine, double check the CO2 levels. About water changes, maybe more are needed after that time? Water flow, is the filter clogged or needs cleanup, etc.

I am not a master my any means, just my 2 cents.

Michel.

Crypts are growing well in my Flourite tank. The Flourite has been in the tank for 15 years.

I remember reading something about it lasting a VERY long time something like longer than the average person lives. Don't quote me on that I just remember something like that when I originally bought mine.

Here I dug up some info
https://www.plantedtank.net/forums/29...rite-last.html

Fluorescent or led? If fluorescent, how old are your bulbs?

• Tubes are about 6 months old and I generally replace them at that interval, Geismann midday and a plant focused bulb
  
• Water changes 15% DAILY
  
• Organic loading can be an issue, I'm way overbuilt with an FX5 Fluval, not an issue at the moment
  
• Flow could be higher but is as every bit as good as it was when the tank grew plants well
  
• Ferts need work...CO2 has been spotty for a while although I've never found Vals (bicarbonate feeders) or Crypts sensitive to CO2...granted the stuff I want to grow needs it!

Have you checked your nitrate levels?

Maybe they are too low, with all those water changes.

Flourite has no ability to grow anything. It looks nice, holds the plants in place and can help hold some of the unused nutrients that are introduced into the tank.

Thanks, I suppose you're so right, in addition neither water or fertilizer grow plants either.

I just tossed out 15 year old substrate that was working just fine. It was too coarse textured and multicolored and I just plain felt like something new after all that time. In fact I delayed the change over just to grow out the Eleocharis 'Belem' carpet so I wouldn't have to buy more.

I had been growing stems just fine then started to have issues. Found that magnesium was the answer. I don't know if the water source for my tap changed or what, used to grow stems just fine. So not only look at getting NPK+M in line, add some GH booster to the tank as well. If you are positive that calcium is fine then drop in a teaspoon of Epsom salt. Inside a couple days after dosing it that darn Rotala was growing properly again.

Can you push a finger through the substrate to the floor of the tank? It's only happened once to me but something was binding the substrate together so I couldn't push my finger through. It was not fun, pulled up the plants, went through the substrate with a siphon to get out the stuff out of the substrate, constantly clogging the poor siphon and having to take care of that then restart the siphon again. I didn't back then but would just take fish out as well so I could take water down to substrate level so water would be clean when refilled.

Slow growing type plants can get most of their nutrients from the water changes and fish food/waste contributions to nutrients. So you may not have had so many plants that they
couldn't "get by" with that.
But root tabs only contain the trace elements needd by plants and not the most used
ones like Potassium.
You are only giving them the Micros ferts and they also have macro ferts that are
needed. I see this as the majority of the problem. Then that daily water change is
counter productive if you are not also dosing nutrients daily to replace what has been take out. Check into the PPS Pro fert system as this is dosed daily.
You can likely use the bulbs one year. For most that is how long they do.

Substrate is loose and moderately clean, my fert routine has been non-existant since I got frustrated. Stems just rot standing up now. Will do some thinking on the magnesium suggestion. Water here is 11 grains or about 160ppm tds so adding hardness wouldn't make sense.

Bump: I've some tropika and other ferts that are intended a NPK ferts, g my water col ferts are zilch, but so far as substrate is concerned it's on par with what most do.

I hope I didn't come off as being snarky as I didn't mean to. Maybe I should have said "Flourite contributes nothing to the growth of plants". There are some claims made on the website for micros being slowly released. While I don't think these claims are actually false I think they're very misleading. Like any other rock it will release minerals as it dissolves in water. That might take a while.
So to your original question, if the flourite still looks good, and still holds the plants it's still going to work for growing them.

Ah, thanks!

Flourite works just fine for years.

So do your dinner plates.

You just need to keep putting fresh food on the plates.

You just need to keep adding fertilizers to the aquarium.

Plants need about a dozen elements to grow. Some are easy to get (hydrogen, oxygen). Some are supplied in fish food, or the water. Some are in short supply, and are the first ones I would look into supplementing.

Fish food supplies quite a bit of N, P and most trace minerals.
Fish food is low in potassium, iron, and calcium (and perhaps magnesium).

Fish supply some CO2, and some CO2 enters the water from the air. These sources plus decomposing plant matter can supply enough CO2 for a low tech tank.

Water with a GH of at least 3 German degrees of hardness usually supplies enough Ca and Mg. When in doubt you could add some GH booster like Seachem Equilibrium. You are looking for a balance of Ca:Mg of about 4 parts Ca: 1 part Mg.
If you know your tap water is low in just one of these minerals you could supplement just that one. Calcium chloride for calcium, Epsom salt for magnesium.

Potassium and iron are the two fertilizers that I needed to supplement even in a low tech tank. Use a chelated iron.
I would also supplement carbon. Excel is a good product, DIY yeast/sugar method works. Pressurized CO2 is best. One sign of low carbon is that the bicarbonate users (Valisneria) and slow growers (Crypts) are OK, but faster growing plants are not. They need more carbon that is entering the water in a form they can use.

Part of the key to this is regular supplements. A substrate with high cationic exchange capacity can even out the supply by holding on to many of the fertilizers until the plants need them. But if the plants have used them all, then the reserve is gone.
If you can follow the estimative index method for several months this will recharge the substrate.
Read the label on substrate tablets, and add these near the heaviest feeders. Whatever these tablets lack will need to be supplied in some other fashion.