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i have a new 20 high saltwater tank that is going to be FOWLR

And i have the following

Right side, has an aquaclear 402 powerhead that is modified to hold a filter cartiage,

Center, has an aquaclear 200 HOB filter

Left, an internal filter(unknown brand)


It is a high tank not long which makes me think that their is alittle bit much.

The powerhead is on a low setting, im really using it to make a current and make bubbles.


It doesnt feel like the current is really strong, but it just looks like it.

So what do you think. Is it too much.

The gph of the equipment would help but I'm guessing your running somewhere around 400gph. Saltwater tanks do tend to have alot of current and 20x turnover is normal for some setups. However it entirely depends what your putting in the tank and how much rock you've got breaking up the current. Some corals and fish would not do well with really high current and others would think it's great. Technically the current is not too much unless you mention you have or are thinking of adding something that prefers lower current.

makes sense.

i want to make a simple saltwater tank, probably not corals at this time just live rock.

As far as fish goes, i want to have a clown fish along with a goby. I have a blue lined damsel in there now.


Thanks for the info.

They should be fine so long as you break up the flow with enough rock and you don't want unidirectional flow like a stream. There's lots of water movement in the ocean but it runs into itself and gets broken up by the rocks. You want rough flow going random directions not smooth flow. Point the powerhead at the glass or the internal filter to accomplish that.

If the flow does look too much for the clown, shouldn't happen unless you don't have enough rock, I'd probably either pull the internal filter and slide the hob down or pull the hob and if necessary turn up the powerhead. HOB filters on saltwater tanks tend to lead to tons of evaporation, salt creep all over the filter and top of the tank, and lots of top offs. Entirely possible to use but annoying enough that I pulled mine off my 20g in exchange for adding a quick filter to my aquaclear powerhead(actually a 402 on half flow rate) and running a refugium with around 150gph.

The fish will use the rock to their advantage if the current is too much. I always suggest 1.5 to 2 lbs per gallon.