Soil substrate pond

[MitchM]

There are other observations I've made, mulm buildup, fish behaviour, effects of temperature, differences of water cloudiness from when first setup to now. I'll try to include pictures as I go.
i'm starting to imagine draining my outdoor pond and putting in a soil substrate with a gravel cap.
Does that make me a bad person?

One problem here is that retail pond plants are suited for warmer water temperatures.
If I want to stock my outdoor pond with plants, I think I'll have to go scavenging to the local waterways.
The plants that I have purchased from retailers are just not doing very well outside. I think it's because of my outdoor pond water temperatures.

 

[MitchM]

Upon closer examination of the minnows in the 40g test tank today, they appear to me to be underfed. They look to have sunken abdomens, so I have fed them some flake food.
This tells me that the 40g is overstocked with three 2" fish. I'm not willing to let 1 or more die to find out.
So now I am falling into the trap of adding nutrients to a "pond" that may or not be able to process the waste associated with that.
Perhaps I will return 1 or more minnows to the big outdoor pond.
Hmmm...

 

[Meyer Jordan]

There are other observations I've made, mulm buildup, fish behaviour, effects of temperature, differences of water cloudiness from when first setup to now. I'll try to include pictures as I go.
i'm starting to imagine draining my outdoor pond and putting in a soil substrate with a gravel cap.
Does that make me a bad person?

One problem here is that retail pond plants are suited for warmer water temperatures.
If I want to stock my outdoor pond with plants, I think I'll have to go scavenging to the local waterways.
The plants that I have purchased from retailers are just not doing very well outside. I think it's because of my outdoor pond water temperatures.

Always best to go native when possible.

 

[Meyer Jordan]

i'm starting to imagine draining my outdoor pond and putting in a soil substrate with a gravel cap.
Does that make me a bad person?

It makes you one that wants to take full advantage of Nature's methodology and not what human's want or perceive that Nature should be.

 

[MitchM]

Upon closer examination of the minnows in the 40g test tank today, they appear to me to be underfed. They look to have sunken abdomens, so I have fed them some flake food.
This tells me that the 40g is overstocked with three 2" fish. I'm not willing to let 1 or more die to find out.
So now I am falling into the trap of adding nutrients to a "pond" that may or not be able to process the waste associated with that.
Perhaps I will return 1 or more minnows to the big outdoor pond.
Hmmm...

One thing to consider is that these indoor ponds do not have visits from outdoor insects, so I guess I will need to step in to provide protein as a diet supplement.
I can put in a couple of these pellets every few days as a substitute.

 

[MitchM]

Differences between water changes and nitrates:

Test tank 0 water changes, nitrates 40 ppm
600g tank 30% water change/week nitrates 0 ppm

The anacharis in the test tank is a much darker green, looks healthier.

Test tank

600g

 

[Meyer Jordan]

Differences between water changes and nitrates:

Test tank 0 water changes, nitrates 40 ppm
600g tank 30% water change/week nitrates 0 ppm

The anacharis in the test tank is a much darker green, looks healthier.

Test tank


View attachment 85554


600g

View attachment 85556

Post seems incomplete. What is your conclusion(s) based on these observations?

 

[MitchM]

Post seems incomplete. What is your conclusion(s) based on these observations?

My conclusions will probably refine over time, but at this point I would say that removing nitrates via water changes negatively affects submerged plant development. I can't say at this time what effect water changes have on marginal plants.

Both tanks have similar substrate, water temperatures and source water.
Plant growth rates seem to be the same.
The 600g is receiving CO2 injection, so that may be artificially stimulating plant growth.
The 600g is lit via 4500K bulbs while the test tank is receiving UV filtered sunlight. Sunlight is 6500k, I believe.
I'm asssociating darker plant leaf colour with a healthier plant.

For now I'm going to stop water changes on the 600g in an effort to raise nitrates.
If I can see a rise in nitrates, I'll stop the CO2 injection.
I would like to encourage plant growth in the 600g as much as possible to control any excess algae growth.

The 600g PH is 7.4 while the test tank is 8.2.
The PH should rise once I stop the CO2.

.

 

[MitchM]

3 days after I did that pruning plus disturbing the substrate, the water turned green again.
I waited for a few days and when I saw no reduction in the floating algae, I turned on the UV. The very next morning, there was a noticeable amount of foam on the surface. My first reaction was to do a water change, but in keeping with advice I have given others on foam developing in their ponds, I am not doing a water change, in an effort to raise the nitrates in the "pond"

My conclusion...by using the UV to reduce the floating algae, I have made more DOC (dissolved organic carbon) available in the water column. The floating algae was using the doc's (and humic substances) as a food source.
So - will string algae come next as a result of the available nutrients?
Time will tell.

I'll do some water tests later today to take some readings.

 

[addy1]

It is a pretty green! Will be interesting to see what happens next

 

[MitchM]

Since I hooked up the UV again, it's much clearer, which is no surprise.
I measured the nitrates and they are still at zero, but after the suspended algae disappears, some plants have grown as much as 30 - 100%.
The PH has risen over 1 week from 7.4 to 8.3. That is probably a result from discontinuing the CO2 and increased algae growth.
I usually measure the PH around mid day when the lights have been on for 8 hours.

There has been no substrate disturbance in the greenhouse tanks, so there has been no apperance of suspended algae.
but - the greenhouse tanks are also cooler. 14c in the greenhouse vs 23c in the tropical tank, water temperature.

 

[Nepen]

this is interesting. I think I was hoping that with no substrate, the roots can take nutrient from water directly... that doesnt seems to be the case since my plant doesnt do well at all. may be i'll get a substrate....

 

[MitchM]

Which substrate did you buy, Nepen? (as you posted in another thread)

 

[Priscilla]

This all seems well beyond my set up, but since you asked about it, here it is.

I have some fish (not too many now), just gravel on the bottom of the tank. One looks pretty good right now (the red plant is fake it came on the rock and I haven't pulled it off). All around the rock is planted, behind it too. As you can see the plants are happy. There are three types of plants in there, they grow fairly low and just look nice.

The other tank is a bit sparse because I just thinned it out which included a water lily that was doing well in there. It was so heavily overgrown on one side there was no space for fish. There are some sort of vine type plants in there, they grow so well its crazy and they get little white flowers on them when they reach the top of the water.

I don't really clean the tanks any more (mostly because I am busy with kids and sick dog), but everything is so happy, I don't see any need to clean it. They are only 10 gall tanks.

 

[MitchM]

Plants look like they're doing well

I haven't looked up yet what plants you have in there, but I'm pretty sure that the center plant in the first pic is one that doesn't like having it's roots in soil, so that was a good choice.
Do you recall if your plants did well from day one?
The plastic red plant is similar to one that I have (real) and in order for it to remain red, it requires a fair amount of iron in the substrate.