How can you judge flow and dead spots?

[Gdbyrd]

Right now I have my tank setup with two powerheads, a penguin 330, skimmer with a Rio 600, a Maxi 900 on the surface pointed across the tank, and a 1200 on the other side towards the bottom pointed up.

I can't tell where the flow stops...where there are deadspots...Are there any secrets/tips to this? I'm just using my hand in the tank and I can't feel the flow a foot or so from the PH's.

I think I need at least two more 1200's. But I don't want to overdo it, there isn't a TON of space in the tank and I don't want to go overboard. I'm just sorta clueless on placement.

I can't follow other peoples tanks because mine is tall. 2 ft wide by 3 ft tall, by next wednesday I'll have 70 lbs of LR in it.

 

[yote]

One method we use at the LFS.Take a small pinch(about the size of a q-tip) of cotton.Roll it into a ball and dip it in bright colored finger nail polish.Let it dry really good(at least 3 or 4 days) and drop it in the tank and watch how it reacts to the flow.
Of course you can the same thing with frozen mysis shrimp too,without the polish of course.

 

[Gdbyrd]

One method we use at the LFS.Take a small pinch(about the size of a q-tip) of cotton.Roll it into a ball and dip it in bright colored finger nail polish.Let it dry really good(at least 3 or 4 days) and drop it in the tank and watch how it reacts to the flow.
Of course you can the same thing with frozen mysis shrimp too,without the polish of course.

Good idea! What exactly do you want to see? As long as the ball doesn't fall straight down I'm good right? I know you had recomended I use korelia's, two on top, two on bottom..but I'm more of a fan of the Maxi's as I can find them locally. What's your estimate on what I'd need?

 

[yote]

What you want to see,is the cotton ball getting blown around.The more chaotic the better.Any place it settle on the sand and doesnt move,is a place where waste will build and compromise water quality.
In a tank like yours,I'd start with 4X MJ1200s.Use Eco Mods on the 2 lower ones if you can.
What you want,is enough chaotic water current to keep detritus and left over food in suspension so that your filtration and skimmers can remove it from the tank.

 

[Gdbyrd]

What you want to see,is the cotton ball getting blown around.The more chaotic the better.Any place it settle on the sand and doesnt move,is a place where waste will build and compromise water quality.
In a tank like yours,I'd start with 4X MJ1200s.Use Eco Mods on the 2 lower ones if you can.
What you want,is enough chaotic water current to keep detritus and left over food in suspension so that your filtration and skimmers can remove it from the tank.

Thanks Yote, one last question. How do you skim the top of your substrate without stirring it up? Specifically sand. I just barely pointed mine straight at the wall and it stirred up a TON of sand, and it's about 5 inches above the surface.

I'll go ahead and pick up a few more pumps sometime this weekend.

 

[yote]

You just have to play around with the placement some.
It'll probably take a few moves to get the right flow without kicking the sand up too much.But I never did like for the flow to just go straight into the glass.Angle it so that the glass deflects it around.