Too much Flow ???

[Trelize]

Having had my tank running for a few weeks now , I have always been thinking that I possibly have too much flow ?

The Cichlids do tend to stay on only the one side of the tank that has slightly less current ,

and tend to chill most of the time in the caves , reading up some have suggested that a little less flow would entice them out a bit more , also the awesome tanks I have physically seen from members on FNZAS did not have as crazy flow as my set up .

I do have a massive 7500lph return pump which I now figure could be overkill !? but I guess I will have really fit fish :lar:

I was thinking of splitting the return and doing a bypass back to the beginning of the sump with a ball valve on the bypass so I can control the flow better ?

I would love some opinions on this please ?

- doing the "bypass"

- Too much flow ?

Thanks

T. :fshi:

[camtang]

How is the water returning from the sump? Spray bar, duck bill etc?

[Morcs]

buy a spare impellor and cut 1mm off the end of each blade and see how it is

[Trelize]

How is the water returning from the sump? Spray bar, duck bill etc?

I have one of these Flow eductor's 25mm

and its screws on to a 32mm inlet , even without it I still have massive amounts of flow , I have found that the educator to give more of a Jetting effect though ...

I was going to do the bypass and possibly remove the educator .

buy a spare impellor and cut 1mm off the end of each blade and see how it is

Could be an option , makes sense, but I don't fancy opening the pump as it is still under warranty .

[camtang]

Someone on here said if you drill bigger holes into a spray bar it decreases flow. You could try that. I make my spray bars from plumbing pipes with a table legs bottom on it as a bung

[Ira]

Having had my tank running for a few weeks now , I have always been thinking that I possibly have too much flow ?

The Cichlids do tend to stay on only the one side of the tank that has slightly less current ,

and tend to chill most of the time in the caves , reading up some have suggested that a little less flow would entice them out a bit more , also the awesome tanks I have physically seen from members on FNZAS did not have as crazy flow as my set up .

I do have a massive 7500lph return pump which I now figure could be overkill !? but I guess I will have really fit fish :lar:

I was thinking of splitting the return and doing a bypass back to the beginning of the sump with a ball valve on the bypass so I can control the flow better ?

I would love some opinions on this please ?

- doing the "bypass"

- Too much flow ?

Thanks

T. :fshi:

On what size tank? Mine has, ideally, around 8500 lph(20X turnover), and at one point had 16,000(36X) and none of the fish had any problem. Except for an angel fish, but they're useless anyway.

[Trelize]

On what size tank? Mine has, ideally, around 8500 lph(20X turnover), and at one point had 16,000(36X) and none of the fish had any problem. Except for an angel fish, but they're useless anyway.

Tank is around 650 litres

[Ira]

Tank is around 650 litres

So, you should be fine. Maybe you could put a couple extra outlets to distribute the flow a bit.

[David R]

I agree that it isn't the flow, but how it is distributed. With a spraybar made from PVC you'll be able to experiment with different amounts, sizes and patterns of holes to direct and control the flow from your return pump without actually reducing the turn-over. When you've got it sorted spray it with some satin black krylon fusion spraypaint and you'll never notice it.

[Likoma]

MO

Fewer deadspots, better water quality, fitter fish, less intank maintenanc, all good reasons not to adjust anything.

With some large rocks you can create eddies in the fast flow for less dominant fish to hunker in behind. A safe zone.

I think strong current is really only an issue in narrow tanks. If it's got a good footprint you're sweet.

[nudge]

spray bars are a good option and it will help lessen the strength depending on how big you make your holes. It can distribute the flow across the whole tank, depending on how you set it up. If you make one to go across 1 end of the tank you can angle it up or down and have the current run from 1 end to the other.

[nudge]

as far as them coming out more you will find they will become more adventurous as they get bigger, i found with growing out juvies they were pretty skittish and hid a lot, this all changed as they got bigger

[flymike]

I have found drilling out the spray bar to be very effective at lessening water speed (velocity) around the tank.

With larger holes in the spray bar the flow (e.g 750lph) stays roughly the same but the velocity decreases

I have three tanks I've done this in 130l,200l,275l.

The two smaller have cf1200s on them, with a single length of spray bar, drilled out to 4.5mm.

The larger 4' tank has a 1m PVC spray bar with 7mm holes, at the back flowing forward and 2x 300lph "wave makers" at one end, I've found this setup quite good. The bar pushes the particles around, up the back and down the front, and the wave makers don't push as well as that pull the particles towards them, which is at the end the overflow is.

This tank holds 275l, and has 1800lph flow through the sump (measured) and 600lph through the wave makers, in this four footer the fish don't evan notice the flow,

and I would like to go higher, but the small overflow cant handle it.

Best mesure the out put of the spray bar to, 7500lph in to the tank would be 125lpm, 2l per second, thats a lot IMO.

[Trelize]

Thanks for all the advice !

Last night I tried a few things with some Hansen fittings I had spare and split the return in the tank with a T piece and 1 90 degree piece and it definitely cut down the current to a point that I am happy with , looks terrible but its only version 1.0 :lar:

Version 2.0 with spray bar should be happening tomorrow .

[Ira]

With larger holes in the spray bar the flow (e.g 750lph) stays roughly the same but the velocity decreases

If anything the flow would increase.

[flymike]

If anything the flow would increase.

Flow is the volume of water i.e. lph, the speed that water is moving (fast or slow) is the velocity

The flow may increase a little dependent on the "working pressure" (basically, letting out pressure the pump puts in that the output cant let out, small holes for instance) there is , which will be low.

Think of it like this.

5000lph pump pushing through a 20mm pipe, the water will spray out the end, pushing water up about 1.5m in the the air

Same pump, pumping the same volume through a 50mm pipe, pushing the water up about .3m in to the air

Roughly same flow and same output, but slower velocity.

Hope everyone can understand this

When this water enters the tank from the flow bar/duckbill, its not only moving the water coming out through the output, but starts to pull the water in the tank with it.

The overflow or filter intake, is only taking in what the out put is putting back in to the tank, so the extra water movement caused by the velocity of the incoming water cycles around the tank.

There will be a little lost in speed due to friction against the tank walls and corners, and obstructions i.e. rocks and plants

I guess in a perfectly round tank this flow of water, caused by the incoming water at a set velocity from the filter output, would build up to the same speed as the incoming water.

like stirring a cup of tea, or making a whirl pool in a swimming pool

I work in sports irrigation, deal with pumps, flows and velocities in pipe networks all day long.

Just my two cents to help with the better good

Mike

[Ira]

The flow may increase a little dependent on the "working pressure" (basically, letting out pressure the pump puts in that the output cant let out, small holes for instance) there is , which will be low.

Didn't I just say that? Larger holes->Less restriction->greater flow.

[flymike]

Didn't I just say that? Larger holes->Less restriction->greater flow.

Yes :bggrn:

But unless your greatly restricting the output at the spray bar ,you wont see a huge increase in lph flow, maybe 5-10lph, maybe not evan a measurable amount. Depends on the set up

Larger holes->Less restriction->greater flow capability

Cant guaranty a large increase in flow (lph) in to the tank

Ira,

Dont take offense :slfg:

Just putting my thoughts forward.

Mike

[Trelize]

Thanks for all the advice ,

Re-designing the inlet was definitely the way to go , and looking back makes better sense , my turnover is pretty much the same but this way I was able to cut down the mad currents that I had , and the fish seem to prefer it to so a win all around ! :bggrn: