A question about flow and resting fish

[howiehok34]

Hi,
Got new tank and everything seems ok so far though already there is a small algae bloom above powerhead.

Anyway, I am a bit paranoid about flow - i have two powerheads in 180l tank that sit rear sides pointing forward so that they cross, and it seems to give flow throughout tank.

Now for the stupid question - should i be looking for a part of tank to not have any flow? The reason i wonder is that surely fish need to rest and not always be in a current - so what's the best compromise in a tank?

Also my two shrimp are quite shy in early days, spending most time on underside of rock in small cave, will they be getting enough food as nothing seems to swirl that way when i put food in? I'm guessing they eat just about anything anyway...


TIA

 

[texdoc77]

Hi,
Got new tank and everything seems ok so far though already there is a small algae bloom above powerhead.

Anyway, I am a bit paranoid about flow - i have two powerheads in 180l tank that sit rear sides pointing forward so that they cross, and it seems to give flow throughout tank.

Now for the stupid question - should i be looking for a part of tank to not have any flow? The reason i wonder is that surely fish need to rest and not always be in a current - so what's the best compromise in a tank?

Also my two shrimp are quite shy in early days, spending most time on underside of rock in small cave, will they be getting enough food as nothing seems to swirl that way when i put food in? I'm guessing they eat just about anything anyway...


TIA

First of all no stupid questions.

Flow can be a bit subjective, but it is more important for coral than fish. That said I am assuming you have some kind of rock where the fish can hide and get out of the flow, that is the main way they rest. (Just don't ask my clownfish, they are constantly out in the water column swimming) As for feeding the shrimp, I have no issues with my shrimp coming out to feed, they are very voracious eaters, give them time, they will eat.

Hope this helps

 

[howiehok34]

Hi - thanks for reply - yes it is 2 clown fish i am referring to - they are always out, and was wondering if this is a problem - maybe when i go to bed they do too!

yes there is 20kg of live rock in 180l tank, so plenty of hiding places as they are tiny and only fish in tank so far...... (only other 2 inhabitants are two hermit crabs, who naturally i don't see much of).

 

[davocean]

I'm sure most fish we keep are used to dealing w/ constant flow most of the time and sometimes far more than what we throw at them.
I would not want any area that lacked flow or had what we call dead spots.
As for your shrimp, they should be fine and should have no problem getting food, or they will come out if needed, if not during day then during night.
Some shrimps are more shy, fire shrimp for example, cleaners usually become pretty bold and usually out all the time.

 

[Duke4life]

Some shrimps are more shy, fire shrimp for example, cleaners usually become pretty bold and usually out all the time.

+1

I've got 2 skunk cleaner shrimp, first few days they were shy but now if I'm near the tank they're out begging for food.

 

[howiehok34]

Cheers all - a shrimp has now shedded a shell - would you leave it in tank or remove?

 

[Rutrag]

I'd leave it. It will either be food for something or dissolve to provide minerals for coral growth.

 

[Duke4life]

Leave

 

[nuxx]

I'm pretty sure for the most part we're running a lot less flow than the ocean can throw at these guys.

Go snorkeling / diving in a surge zone and you'll see what I'm talking about. I'm pretty sure my powerheads wouldn't toss me around like a rag doll.

That being said, I do like to run my powerheads at a much decreased constant speed at night. Partial for the fish (I guess), partially for noise. The waves can make a bit of noise, the lower constant speed is dead silent. I can hear it from the living room, so at night I'd like it silent.

I also have "clouds" come out during the strong period of lighting during the day to give the coral a rest... I'm sure it does nothing, but makes me feel good about it haha

 

[davocean]

Personally I would not lower flow at night, if anything we should be turning flow up, or at least leave as is, that water flow helps to oxygenate the water, stabilize PH, which is important in our small contained systems.
I understand though, if noise is an issue and keeps from letting sleep I guess it may be necessary for your particular situation.
The cloud cover feature does not do much, but it is a cool visual, that is the only showy light feature I would use.

 

[Boom]

Personally I would not lower flow at night, if anything we should be turning flow up, or at least leave as is, that water flow helps to oxygenate the water, stabilize PH, which is important in our small contained systems.
I understand though, if noise is an issue and keeps from letting sleep I guess it may be necessary for your particular situation.
The cloud cover feature does not do much, but it is a cool visual, that is the only showy light feature I would use.

+1 about the flow. Lost my mp 40 and replaced with a smaller pump. I gradually lost almost all my corralline and started fighting gatgo. Switched to a bigger power head and doubled the size of the return pump a month ago. Corals growing faster than ever and corralline coming back fast. I changed the aqua scape and flow pattern to a gyre after reading this http://www.advancedaquarist.com/20...t to do it before lights on in the a.m.:cool:

 

[Ls2Goat]

Fish will adjust to flow, they will find a spot to sleep. As stated above flow is more important for coral, I use vortec powerhead that utilize a sleep/night mode that drops the flow down to around 10-15%. Some coral/fish will take advantage of this some won't.