powerhead placement and dead spots?

[dragonfisher33]

so i have rearranged the live rocks and played around with the placement of the powerheads (Koralia 425 and Aqua clear). Just recently i have been through a diatom breakout and slowly but surely it's going away. what i'm noticing now is that there's brown spots on the corners of the tank. are those dead spots due to a good water flow? or dead diatoms? can someone recommend a way of getting rid of them or a better placements of the powerheads if the brown stuffs are the results of the lack of water flow?

Placements: Koralia is on the right rear corner slightly angled downward
Aquaclear is on the left center with Hydor FLOW deflector

 

[erichm20]

I'm in the "high flow" camp and like at least 20 x tank volume. I am currently running at about 28 x and want it a little higher like 35 x.

That could be build up due to a dead spot but I think diatoms can form even in higher flow areas. Now if you see detritus or uneaten food collecting in an area it is definitely a dead spot and you will want to adjust.

 

[dragonfisher33]

I'm in the "high flow" camp and like at least 20 x tank volume. I am currently running at about 28 x and want it a little higher like 35 x.

That could be build up due to a dead spot but I think diatoms can form even in higher flow areas. Now if you see detritus or uneaten food collecting in an area it is definitely a dead spot and you will want to adjust.

well, the thing is that i don't have many things in the tank. two hermit crabs one pistol shrimp, and one goby. i don't overfeed. but i have no idea what's causing the sand on the corners to "turn"/look brown. it's definitely not diatom or algae. it looks fuzzy but not any sort of hair algae.

 

[Grizz]

Try aiming the power heads at each other the flows crashing into one another will give you a good random flow.

 

[dragonfisher33]

Try aiming the power heads at each other the flows crashing into one another will give you a good random flow.

won't that cancel the flow from both powerhead and create less movement of water?

 

[Grizz]

You would think so but it dont, it creates a random flow through out the tank

 

[carey]

I position my powerheads slightly upwards to get surface agitation and towards the front glass. The two flows meet and crash causing chaotic flow.

 

[dragonfisher33]

oh really? i can try to reposition the powerhead on each side a little bit. but do you guys think i have enough flow? one is koralia 425 and the other one is AquaClear 50

 

[Grizz]

I'd take that AC 50 out and add a 750 or at least a 450 to that side

 

[dragonfisher33]

I'd take that AC 50 out and add a 750 or at least a 450 to that side

well, the reason why the AC is there is because i have a FLO deflector attached to it to create a "random" flow.

 

[Grizz]

Move it to the back center of the tank That will take care of those corners

 

[dragonfisher33]

also i ordered a Koralia 750 from Amazon that i'm going to replace the 425 with because i feel 425 isn't much for my 29gal at all for some reason, maybe due to the live rock interfering with the flow? the spare 425 will go to a different tank after that.

 

[Grizz]

If it were me i'd run both the 425 and the 750

 

[dragonfisher33]

If it were me i'd run both the 425 and the 750

as well as the AC?

 

[Grizz]

Yup Im running around 10k gph. in an 8 ft long 180 IMO there's no such thing as to much flow I'D take the ac out and try the two hydor's first