Using Oil-Dri for cheap substrate?

[sowNreap]

Originally Posted by aztx

"Liquid rock" is a term used by many to describe water that is extremely hard and alkaline. The water in my area, for instance, has an EXTREMELY high carbonate content (and mineral content in general), so it's often referred to as "liquid rock".

Oh ok.. thanks. I thought it was something I could buy to soak my STS in. LOL

[Diana]

I suppose you could make some liquid rock!
Since these materials remove the KH, you could make some high KH water to soak the substrate in, see if it would reduce the problems with KH being removed later, when things are set up.

I suppose you could also add fertilizers. With a high cationic exchange capacity you could pre-load the substrate.

STS in the 88 gallon tank is still looking good, the water is a lot clearer. (I am running 2 canister filters on it).

[sowNreap]

The rinsed STS has been sitting in my 18 gallon totes for so long now it's probably dry again. LOL Yeah I should have pre-loaded it. May still do it yet. I seem to keep putting off changing the substrate out since it seems like it's going to be a big job and would prefer to have it some on 1 day.

So it only took you 1-40lb bag to do an 88 gal tank. I bought 2 thinking I would need more than 1 bag for my 75 gal. I guess I'll have plenty.

I added several handfuls to my almost full of water tank a while back right before my bluegill started making his nest just to see how much of a mess it would make with all his tail fanning ... wasn't bad at all. And what little he did stir up settled quickly with almost no clouding of the water. Of course that was just 1 little area and it did get mixed into the gravel, but was happy enough with it's performance to do the whole tank. Someday soon I'll get around to that.

[Diana]

Yes, the 40 lb was barely enough. 5' x 16", and the substrate would be barely 2" if it was flat.

Tank is quite clear, now.

Ammonia is disappearing, but I think it is the plants. No nitrite yet. Nitrate is about consistent with the fertilizer dosing, or maybe a bit higher. I have not added much in the way of nitrifying bacteria. Just what was on the plants. The plants came out of tanks with very small bio load, so very few bacteria came with them.

KH is still as high as the tap water that I filled the tank with.

[sowNreap]

I won't be sloping front to back but may have some small mounds and valleys. Figured I'd have 4" in some spots while others may have only 2". I calculated for 3" if it was flat across the tank so bought an extra bag. I sure didn't want to run out while in the middle of re-doing the tank. Don't think the fishy's would like that. It's going to be stressful enough for them as it is. Plus I can always use the extra in another tank.

Keeps us informed how the KH does if you don't mind.

[Diana]

Something odd going on... the KH is rising.
Uh-oh... I used some pond fertilizer tablets that were in poor shape- more like powder to granules, not tablets any more. Dusted it on the bottom, under the substrate.

Fishless cycle chugging right along. Ammonia and nitrite readings high enough to grow plenty of bacteria.
Nitrate, too, but I add fertilizer for the plants, a blend that includes N. (plus the pond ferts!)

I may have over done the ferts. Gotta move more plants into the tank.

[Trickerie]

Weird. Did you use all sts? Or just a cap?

[Diana]

All I used was the Safe-T-Sorb, 40 pound bag.
The only additive was the pond fertilizer tablets, and they were pretty beat up. The granules went under the substrate.

The filters have an assortment of sponges, floss and ceramic bio-noodles. No chemical media.

Since then I have been adding ammonia for the bacteria, and fertilizers (macros and micros) for the plants.
KNO3
KH2PO4
K2SO4
CSM+B
Chelated Iron
Excel

The bacteria are removing about 1 ppm ammonia each day, so I add enough to bring it up to 3 ppm, about every other day. It got down to 1 ppm this evening. Nitrite is high. (I have a hard time telling the difference in the colors on the strips, and my API NO2 test is so old it no longer reacts)

KH is coming back down, and the pH is a bit lower. I think there was something in the fertilizer tablets. But what is making the KH drop so fast? The bacteria can't be growing THAT fast! They do use carbonates, but this is way more of a drop than that!

[Trickerie]

The sts sucks carbonates out of the water like a vacuum. This will continue for quite a while since you used 40 lbs. My suggestion is to buffer it quite high each water change to let the sts charge itself quicker. I used only a cap of it, and it still took a few weeks to stop

[Diana]

Yup, I bet the STS is taking over and removing KH. KH is totally crashed and pH is at the bottom of the chart. Added 2 tablespoons baking soda; this ought to raise the KH by about 4 German degrees of hardness, and bring the pH up a bit.

I added a lot of rock as a background, stirring the substrate some. It clouded up while I was working, then settled down really fast. This is a very good substrate, that way. It has not even been an hour since I was up to my shoulders moving rocks around, and the water has only a slight haze remaining.

[rodcuda]

What did the substrate pull the ph down to?

[starquestMM]

I just converted a 10gal to sts and am really likeing it. It dropped the kh from about 14 to 8 and ph went down from 8.2 to 7.6 so it really does pull in the minerals.

I'm wondering if it would work to take some fresh dry sts and "load" it using ferts? Basically take some RO/DI water and dissolve whatverer micros and macros into it. Then add the sts for a week or so, rinse and use.

[Trickerie]

It does work and many have done it.

[Seattle_Aquarist]

Originally Posted by Diana

Yup, I bet the STS is taking over and removing KH. KH is totally crashed and pH is at the bottom of the chart. Added 2 tablespoons baking soda; this ought to raise the KH by about 4 German degrees of hardness, and bring the pH up a bit.

Hi Diana,

I realize that baking soda will raise the dKH, and I use an online calculator to determine the amount of baking soda to add to accomplish the desired change.

How were you able to determine the dGH (General / German) change that would occur by adding the two tablespoons of baking soda?

[Diana]

Roy, I have done this before with Soil Master Select. The first time was in a 29 gallon tank, KH and pH bottom of the test (KH=0, pH =6 or lower).
Add 1 teaspoon baking soda, let it circulate. Test. KH =2 German degrees of hardness, pH = 6.2. Repeated several times on 2 tanks the same size, then later similar results with other tanks ranging from 10 gallons to 125 gallons.

So... 1 teaspoon in a 29 (Done over several years, many tanks) = 2 degrees
so... 2 tablespoons in a 88 (The tank under discussion today) = 4 degrees

There are 3 teaspoons in a tablespoon, so I added 6 times as much to a tank that is 3 times as large, so the KH change ought to be twice as much.

It was late yesterday when I added the baking soda, so I did not go check it after it had circulated, and by now the substrate has probably removed it. I will post the test results later, and what I do about it.

I also have pH test strips that came from a lab, and test lower than the aquarium tests, so I will use those. They are probably more accurate, too.
KH test is API and Jungle test strips. I can use double the water sample in the API test to fine tune the numbers. No, the tests are not calibrated. While I am willing to pretend that I have results down into decimal places, I know it is not that accurate.

I am looking at the big picture:
This substrate removes pretty much all the carbonates from the water.
This allows the pH to drop way too low for the nitrifying bacteria to reproduce. (I am running the fishless cycle on this tank, remember)
So I want to fix it.
This would mean raising the KH to at least 3 degrees, and probably higher. (The original work identifying the correct species of nitrifying bacteria used a KH of about 8-9 German degrees of hardness, if I remember).

starquest, I think that is a good idea. These products have a high cationic exchange capacity, and will indeed soak up a lot of fertilizer. When I was using Soil Master Select and the EI method of fertilizing I think I got that substrate really well saturated with fertilizers. When I stopped dosing the tanks for a while the plants continued to do well for a couple of months. I would be leery of using too much fertilizer, though. You would not want so much that it would leach out into the tank water. I understand what a dry start is, but the root zone is wet, and too much fertilizer in the root zone may not be good. So, soak the substrate in fertilizer rich water, then drain away that water and refill with ordinary water (RO, tap or whatever- not enriched with fertilizer).

On the schedule for today: Water change. The ammonia removing bacteria are growing like crazy and have spiked the NO2 too high. I am not sure about the NO2 removing bacteria. It is too soon for them to really be growing that well, but the NO3 is high, too. I am thinking some of the NO3 reading is from fertilizer, and some from the bacteria.
I will test tap and tank before and after. (Garden plants are going to love this water!)

Water company adds sodium hydroxide to raise the pH. I suppose that is another item removed by the substrate, or else why would the pH drop so much? Normally the tap water is KH 4-5 degrees and pH high 7s, occasionally low 8s.