Central Taiwan Biotope Creation Log and Journal

dan518

Potamotrygon
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Looks to be coming together nicely, what is the turnover going to be?
 

cockroach

Goliath Tigerfish
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The circulation pump is rated 7500L/h
The canister is only rated 814L/h.
Taking away 15% for losses would put it at about 7100L/h or so.
That makes turnover roughly 25x.
This sounds like a lot but considering the flow of the water it is not much at all.

The water is moving but not as linearly as I expected. I may add another smaller circulation pump, maybe 3000~3500L/h and have that set on a timer with the lights. This would take the turnover to about 36x. But only while it is "day time" for the fish. Leaving night time to rest.

Again this is, in theory, and somewhat in practice, a 45cm x 45cm x 120cm column of water moving in a single direction so does not have the thrashing effect it would in a "square" tank. The column is 64gal of flowing water.
That is 1/4 of a cubic metre.

As the propellers are below the substrate, there is no jet effect that will hassle the fish leaving them a semi-homogeneous current column to play in. (If that makes sense)
 

dan518

Potamotrygon
MFK Member
Sep 20, 2014
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The circulation pump is rated 7500L/h
The canister is only rated 814L/h.
Taking away 15% for losses would put it at about 7100L/h or so.
That makes turnover roughly 25x.
This sounds like a lot but considering the flow of the water it is not much at all.

The water is moving but not as linearly as I expected. I may add another smaller circulation pump, maybe 3000~3500L/h and have that set on a timer with the lights. This would take the turnover to about 36x. But only while it is "day time" for the fish. Leaving night time to rest.

Again this is, in theory, and somewhat in practice, a 45cm x 45cm x 120cm column of water moving in a single direction so does not have the thrashing effect it would in a "square" tank. The column is 64gal of flowing water.
That is 1/4 of a cubic metre.

As the propellers are below the substrate, there is no jet effect that will hassle the fish leaving them a semi-homogeneous current column to play in. (If that makes sense)
Yeah it make sense, when I was planning a high flow tank I used meters per second to work out how much flow I wanted.
1 kilometer per hour = 0.27 meters per second, or 3.7 seconds per meter. So a 1.2m tank would take the flow 4.4 seconds from end to end, 1 kph is a fairly slow flowing stream (maths might be off)
Have you tried putting cowling around the end of the wave maker, I would have thought it would be sucking water back along the sides of the tank, underneath the glass table.
 
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cockroach

Goliath Tigerfish
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This is the reason I think another pump would help. It would make a wall of forward moving water stopping the sides from backing around.

I think I am also going to take a length of PVC pipe, maybe 2" or more, and cut it into a quarter pipe to help the flow round the bottom corner back into the display area. This, at least in my mind, should help flow as it will be the path of least resistance.
 

cockroach

Goliath Tigerfish
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Just added another 7500L/h circulation pump making 15,000L/h total now. I much prefer the new flow and will post a short clip soon.
 
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dan518

Potamotrygon
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Just added another 7500L/h circulation pump making 15,000L/h total now. I much prefer the new flow and will post a short clip soon.
Glad you got the flow how you want it, looking forward to seeing the progress.
 

cockroach

Goliath Tigerfish
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The double pump combo seems to be doing what I want it to.

Pic of both pumps. They are pointing up at the moment but will probably end up facing the bottom glass more to ensure nothing settles there.
Double Pump Pic.jpg

This is the clip of the water movement now. There seems to be less "backwashing" below the false bottom.

I will be emptying the tank tonight or tomorrow and siliconing the last few pieces of glass.
a. the plastic grating support for each side
b. The gravel border to hold back smaller pieces of gravel

Once that is done. The fun can finally start.
 

dan518

Potamotrygon
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Sep 20, 2014
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The double pump combo seems to be doing what I want it to.

Pic of both pumps. They are pointing up at the moment but will probably end up facing the bottom glass more to ensure nothing settles there.
View attachment 1339933

This is the clip of the water movement now. There seems to be less "backwashing" below the false bottom.

I will be emptying the tank tonight or tomorrow and siliconing the last few pieces of glass.
a. the plastic grating support for each side
b. The gravel border to hold back smaller pieces of gravel

Once that is done. The fun can finally start.
Looks like you have a pretty good linear flow, looking forward to see how it all turns out.
 
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cockroach

Goliath Tigerfish
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Test fitted the left side grate. I think it will work fine.
P_20181017_213012_vHDR_Auto.jpg

Left and right gaps are 8cm and 7cm respectively. Not sure yet which side, intake or output, for false bottom is getting the extra cm.

This is the kind of crap a fuss about. Can be irritating. lol
 
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cockroach

Goliath Tigerfish
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I finally got some time to silicone the grate supports and the gravel retaining edges. This is a rough draft of the tank and I will be editing during this week.

I went to the stream and collected some rocks, pebbles and gravel.
P_20181020_164938_vHDR_Auto.jpg

I already realized I do not need to wait for the algae to grow all over the rocks when I can just collect algae covered rocks from the stream and be ready to go.
P_20181020_164943_vHDR_Auto.jpg P_20181020_171658_vHDR_Auto.jpg

Filling a the gaps with gravel. I only put a thin layer to keep the weight down. In total I must have used 45-50kg (99-110Lbs) of hardscape materials.
I found some glass load bearing calculators online and between a handful of them I came to the conclusion that 70-80kg (154-176Lbs) was the max I would go.
I also wanted some light to filter through to the false bottom.
P_20181020_172706_vHDR_Auto.jpg
P_20181020_172721_vHDR_Auto.jpg

After it was set up I did the "earthquake test". That is basically grabbing the tank by the top bracing and shaking it back and forth and side to side to make sure nothing will collapse during a real earthquake.
P_20181020_174621_vHDR_Auto.jpg
An better angle to see the whole scape. P_20181020_174631_vHDR_Auto.jpg
Some details
The left "intake" side. Some of the stones overlap just to break up the straight line of the grate edging.
The stones in the top middle make a small cave, the two large stones on the right make a cave that can house a few fish. The bottom stone also provides shelter from current.
The large middle stone and two supporting stones create a nice little eddy for the fish to rest in.
P_20181020_174646_vHDR_Auto.jpg
As it started filling it created channels.
P_20181020_175233_vHDR_Auto.jpg

Looking for the left side of the tank.
P_20181020_174657_vHDR_Auto.jpg

Here you can see the two caves.
P_20181020_174703_vHDR_Auto.jpg

Top view of the right "output" side of the tank looking left. Behind the largest rock is a mound of gravel to add another place and different type of area the fish can rest in.
P_20181020_174729_vHDR_Auto.jpg
The right side of the tank. The back most rock on the right is also a small cave.
P_20181020_175132_vHDR_Auto.jpg
The round stone in the middle is almost completely a cave underneath.
View attachment 1340632

Filling up.
P_20181020_180030_vHDR_Auto.jpg
The tank 5 mins after filling. The wood was adding for something a little more organic looking.
P_20181020_182540_vHDR_Auto.jpg

I plan to go and get larger rocks covered in algae. I also want to get one or two floating mats of algae to act as "cover" for the fish. It should, if logic prevails, stay on the left side of the tank.
I will look for a few long filaments to drape around the wood making it look like it got snagged in the current.
 
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