The effects of Current and some new options, considerations for planted aquarist

[Tom Barr]

Im often troubled by the suggested flow rates for planted aquariums holding fishes as well as plant's.
Some suggest that for proper CO2 /nutrient dispersion, that up to 10 X the water volume in turnover is required.
I wonder how many fish species would appreciate this much current given that many would never see this much movement in the wild or average aquarium.
Have also become aware that for some,,fishes are almost after thought in planted aquaria, How sad.
I have seen photo's ,video's of tanks with Angelfish for example that fishes were actually listing at near 45 degrees due to flow throughout the tank.
The Flow never seems to be enough according to some to get proper CO2 through out the tank, How bout reducing plant mass ,pruning,trimming more often?
At what point are folks happy with growth? I cannot tell. What is minimum flow rate for desired growth?

Where do you think many of the fish live?
Rivers, Discus etc.....

We have a large volume and the Angels are massive and are all F2's now.
Never seen another tank.

They eat like pigs, my cardinals will pick my arm hair like Barbs.
Exercise against the current. With a decent design, there are places they can "rest", but fish are well designed to swim after all, and it takes much less energy to do so vs a land animal moving.
When they are active, they eat better and behave differently. Same for people, if you exercise, you are healthier and stronger.

I see no reason why this does not also extend to fish, dogs, cats, livestock etc.
This is not about extremes, however, good current is not about the most, the highest wattages etc.
Just some decent rippling and good current.

Hard to say what is optimal for a given tank, depends a lot on the fish, load, aquascape goal.
More open designs can withstand more current.

Dense thick Dutch scapes?
Not much.

Still, one can provide a good ripple along the surface even in such thickly planted tanks.

This tank had thicker growth etc, but moderate current.
Also had few fish.

I like plants, but also like fish, and I'd like to see them once in awhile.
Many of my scapes have tended to simplicity for this reason.
I can view the fish and enjoy watching a school swim against the currents.
Reminds me of swimming in streams/rivers as the fish go by.

 

[jerrybforl]

Wow Tom that is a beautiful Dutch Scape. I wish I had those kinda skills.

 

[1077]

Yes, fishes do indeed inhabit river's. I spend near 200 day's a year on the missouri river that runs through the city here.All I am saying is that given a choice,,many small fishes, choose back water eddy's out of the main channel and associated current's.This is where large predatory fishes such as Blue catfish, andFlatheads that I fish for come to to seek out these small baitfish.
You could seine for these small fishes (baitfish) as I do, long and hard in area's of strong current and have little to show for your effort's. The majority will be found in afore mentioned Creeks,eddy's,side channels,off the main river and out of the current.
Have not viewed Discus in their natural habitat, but have heard from those who have, and they often report that these fishes are found in large number's among root wads near the bank out of main current and where vegetation is at times sparse, due to tree canopy overhead which filter's out considerable light.

 

[Tom Barr]

The high flow rates in an aquarium are painful small compared to a river however.
1-2 knots is a heck of lot of current if you tried to recreate that across the entire cross section of the tank.
1 knot is not much current. In thick planted rivers, Rainbow, Ichetucknee etc, fish and other critters hang out in the open spots in the plant beds, crawl around the outer edge etc.
It's no trout stream. Even trout hang out in the slow sections a lot of the time.

So trout are not much different compared to discus on this level, I find them, as well as catfish etc, bass, etc under logs or near the edge, good place to fish and good place for them to hide from predators etc.
But few would say current is bad for trout for some reason. Taste good.

If the place has trees, that's a plant!
Flooded forest are aquatic habitats!
It might not be what we like to think as aquatic, but they are.

Hyacinth is common and other floating weeds. These are mostly only able to grow where there is a good source of nutrients and run off.
The water in the region is actually very pure and there's not much nutrients in it, this is good since it prevent aquatic weeds from taking over and choking the rivers there.

Missouri river?
Haha! Loaded, but far north to avoid many of the weeds, but Egeria, Crispy pondweed and Hydrilla can easily grow there.

We have a bad sponge plant infestation here and a real bad Hyacinth issue in CA.
Hydrilla and Egeria as well. Lake Tahoe has milfoil and Crispy pondweed now, and it follows the boater's, their patterns and the where the nutrient run off is.

 

[Tom Barr]

the water current in my 180 Gal is high, but it's still only about 1/4 to 1/2 knot tops and this is only in about 20% of the tank, well under 1/8th knot in about 50% of the tank and even less elsewhere. This pushes the water around and through the plants, and the open space in the front of the tank is where the fish hang out.

If they want some exercise, they can swim in the current.

 

[dutchy]

GPH flow numbers in a tank seem to be very large, in reality it's very slow. When people hear I have 2000 GPH flow in my 180, they think all fish are stuck to the opposite window. When they see it, they are surprised that just the plantleaves are moving a little bit. Between the plantgroups, flow is even less. Some species love the flow, like hatchets, congo tetras and celebes rainbows. They get right in front of the powerhead and play around. They don't have any problem to overcome the current.

Stationary waters with low O2 levels, that's the problem.

regards,
dutchy

 

[Cyclesafe]

High flow, well distributed, from a internal pump fitted with a pre-filter has made an enormous difference in my tank. The water is crystal clear, there is almost no detritus, no algae (so far), no BGA, and the fish all line up in formation in front of it. Of course, other things have to be done right too. My only concern is heat build up in summer.

 

[skerzfan]

I'm at a crossroads setting up my 90 gallon. It will be CO2 injected, 2-3 T5HO bulbs. Primary filtration is Eheim 2260 canister with spray bar at end directed slightly downward with intake at opposite rear corner. My intent is to use a Eheim 1103 needle wheel pump through a venturi reactor 2" X 20". What are thoughts on a spray bar return the length of the back, a couple of inches below the surface, directed at an angle aimed at hitting the front glass midway down? The other option I'm looking at would involve two or three Loc Line flare nozzles attempting to create a well distributed flow the length of the tank.

Aesthetically I'd prefer the relative in-obtrusiveness of the nozzles. I'd think I would also prefer the lengthwise more 'natural' lengthwise flow, I just don't think it will distribute the CO2 as thoroughly. Granted, between the two pumps I feel I'll have ample circulation in regards to turnover. The wife suggested I try out both methods to see which works best. That's what I may end up doing.

Thoughts?

 

[Jim Miller]

One approach I've seen work well is spray bar at same end as filter intake. Flow goes across top drops then returns across the bottom. From the front the flow appears circular, either clockwise or counterclockwise depending on which end the plumbing is located.

Jim

 

[barbarossa4122]

GPH flow numbers in a tank seem to be very large, in reality it's very slow. When people hear I have 2000 GPH flow in my 180, they think all fish are stuck to the opposite window

I have 1500 GPH (2 Koralia Evolution 750) , not including the flow from the XP4, in my 55g tank and 850 GPH (2 Nanos 425) , not including the flow from the XP3, in my 30g breeder.

 

[1077]

Lowly Non CO2 80 gal planted tank. 96 watts T8 lighting, Eheim 2217. All plant's ,fish,(approx 80) doing well. Even Ludwigia Glandulosa remains not so much red,,but purple. Crypt Parva sending out runner's along substrate.

 

[gforster]

So, How would I maximize the current in my tank? 75 gallon, XP2 and XP1 with lily pipes on opposite corners (intake and outake from each are together). I am considering getting a koralia 2. What would the best placement be?