Saf-T-Sorb vs. Pool Filter Sand - Substrates

hoppycalif · 10-24-2020, 06:54 PM

I have been using Saf-T-Sorb for a couple of years now, due to its very low cost and the belief that it should be a good substrate, but I think I have noticed that it doesn't do very well during the first few months in a planted tank. As I remember my experiences with pool filter sand were much better during those first months.

About a year ago I modified a 10 gallon tank by putting an acrylic divider in the middle, making it a two 5 gallon tank, where both halves of the tank get exactly the same light at all times. That tank has rested in a closet for much of that year, when my attempt to put El Natural style set-ups in it didn't work at all well.

So, one of my friends here remembered that tank and hinted that I could do a comparison test between pool filter sand and STS. I just laughed at the idea, but it soon stimulated me to want to play scientist again.

So, I now have slightly modified the tank to make sure no water gets traded between the two halves, then purchased some pool filter sand and a new bag of STS (only to discover that I already had plenty of it stashed in an outdoor closet.) Tomorrow I will set it up with identical conditions, identical depths of substrate, identical plants (just a few), Identical water, identical fertilizing, and watch them for variations in how they make it through the first few months.

This will not be El Natural set-ups, but more like low medium light, with light fertilizing and API CO2 Booster dosed as recommended on bottle. My tap water is pretty soft, so I will dose both with GH booster to get close to about 6 dGH, to be sure there is calcium and magnesium for the plants. I don't plan to put any fish in the two tanks, but that is still undecided. The plants are easy to grow, beginner plants, possibly only 2-3 stems in each tank.

If I was an entrepreneur I would set up a betting booth and make some $$ on this! (But, I'm much too lazy to ever try that!)

mistergreen · 10-25-2020, 08:11 AM

Nice!
Try stems & rosettes. I wonder if the plant type matters.

Michael · 10-25-2020, 09:00 AM

Great idea!

The recent discussion on STS led me to a hypothesis: STS gives better results with hard, high pH water (like mine) than with soft, low pH water (like yours and Diana's?).

Your experiment won't test this directly, but will give us some clues. If I were dedicated enough, I would set up the same tank as yours, only with STS on both sides and my hard tap water in one and some soft water in the other.

hoppycalif · 10-25-2020, 07:22 PM

Today I got the tank filled with water and the two substrates, installed tiny filters in each half, and gave it a lot of thought - exhausting! The substrates I washed equally, 3 sessions with a hose, with the water being near clear when I quit. I taped a background to the back of the tank to make sure the near-by window doesn't affect the light intensity in the tanks.

I'm going to use plant cuttings - stem plants - from my existing tank, probably no more than 3 plants per tank. If I were to try to use rooted plants I would want to put a soil base under each substrate, and I don't have any rooted plants anyway, except 3 vals.

EDIT: My light intensity in both tanks is 34 PAR at the substrate. That is more than low light. The tanks are now planted, with 2 each rotala cuttings, probably rotala rotundifolia, and one hydrocotyle cutting. The cuttings are from the same plants and are very close to being the same size, and are planted in the same positions in each tank. I'm fertilizing every other day at the minimum level in the Estimative Index method, plus 0.5 ml of CO2 Booster daily.

hoppycalif · 10-28-2020, 02:17 PM

My cell phone problems made it impossible to use the camera on it, so I bought a cheap camera on Amazon, and took my firs pic of the pair of tanks: You can see the most obvious difference between the two substrates. The pool filter sand is many times more reflective than the STS. It doesn't have an significant effect on PAR, but it does make looking at the two side by side very difficult. Next pics will be one half at a time.

GadgetGirl · 10-29-2020, 09:45 AM

Subscribed to this thread! Very interested in your results as I'm a huge STS/Oil-Dri fan and dislike sand because it always ends up looking so bad. Purely esthetic reasons.