Hi everyone,

I have a 75 gallon tank that's been up and running for about a year now. Substrate is black fluorite sand, lighting is a single Finnex Ray 2 so medium lighting.

When I started a year ago, all my plants seemed happy with my dry fert regime which consisted of enough potassium nitrate & potassium phosphate on Monday/Wednesday/Friday to keep nitrate levels around 20ppm and phosphate at 2-3 ppm. On Tues/Thurs/Sat I would add 5mL of Flourish Comp. 50% WC each Sunday.

Now, a year later, I am doing everything the same but my plants just aren't growing with the same vigour they once were. I'm hoping to get some advice as to what I should try changing. Increasing the dose of Flourish Comp maybe? Do you think my fluorite substrate was previous supplying something that has now petered out?

Had to start using root tabs. Osmocote plus in gelatin capsules, I use 6 in my 60-P. Consider going that route, dosing the column isn't going to do much for substrate feeders

There is a thread here somewhere, which I can't find, that described a good test about whether or not you need substrate fertilizing for "heavy root feeders". It showed that the "heavy root feeders" grew as well with or without substrate fertilizing.

Even my floating plants have diminished in size. I'd say the leaves on my Salvinia are a quarter of the size they used to be. Putting in some root tabs or osmocote is a good idea for my crypts but that won't help my floaters so I guess I'll have to experiment with changing my dry ferts too.

Well,floating plant's can cut light down from medium to low without constant removing to prevent this.
This could slow down growth for plant's under less light penetration .
Also possible the plant's have grown to their potential size,and some trimming of the top's ,replanting the top's, and or removing the bottom portion's ,or thinning out of bunch plant's is in order.
Large plant mass after a year, might need more nutrient's than it did for first year.Can alway's add root tab's to substrates also.

Are you running co2?

Yep, I'm running CO2 with a diffuser. Drop checker is green.

I used to hardly be able to keep up with scooping out the floaters they grew so fast. Now they are tiny and they are certainly not multiplying like they used to. There is currently lots of light getting through to the lower plants.

I tried increasing my dose of flourish comp and I think it may have backfired.... My wisteria is all malformed now at the tops where the new growth is. I'm going to back off again on that.

Something I've noticed that may or may not be related is that snails have never thrived in my tank. I always considered this a bonus because I don't want to be overrun with them, but they never seem to grow well and their shells get pale and whitish and they seem to die prematurely. It seems to be even more true now - I just had a look around and could only find a few small snails.

All my fish are fine, very healthy and no issues.

Sometimes when snails aren't doing well, it is a lack of calcium. This could affect the plants also.

What about light? What are you using? Could your bulbs have dimmed some? With newer T5 and LED, this isn't usually an issue, but doesn't hurt to ask.

The op is using a ray2. The first thing I thought was calcium as well when you mentioned the snails. What's you gh and kh?

this thread right?
https://www.plantedtank.net/forums/33...t-fiction.html

And lack of calcium causes exactly this - small and deformed leaves. Your GH should be really low though - probably about or below 1 dGH.

That's a fun experiment, but it doesn't dissuade me from using root tabs. If there was ever a plant we considered a "root feeder" it would be a sword, and the sword showed the most dramatic growth difference between substrates. I run a low tech tank and like to stack the odds in my favor as much as possible...