Common sump - algae in one tank, not the other

[Kann]

Hi, all.

I have a 210 reef and a 60 frag tank plumbed into a common sump. My 210 is spotless, I mean not a bit of algae anywhere. My frag tank has green/brown hair algae everywhere! It grows on the glass, power heads, frag racks, and even on the frag plugs!

My 210 is lit with 250 watt Radiums and 4 T5's. The 60 gallon frag tank has an 8-bulb T5 fixture. Nitrates and phosphates are both undetectable using Seachem and Red Sea test kits. The photo period for both tanks is about the same... T5 on the 210 for 14 hours/day, halides for 6 hours. Two of the T5's on the frag tank on for 12 hours and all 8 on for 4 hours.

I have a pair of MP40's on opposing sides of the frag tank providing plenty of flow. A pair of Gyres on the 210.

I'm running Chaeto on a reverse lighting cycle with a Kessil H380 fuge light and it grown like crazy! I throw about a basketball size amount away every couple weeks.

I'm stumped with why I would have algae in the frag tank but not a bit in the main display tank. The only difference I can think of is lighting. Intensity seems to be higher in the main tank than the frag tank though I haven't measured with a PAR meter yet. I was using a combo of

• 5 ATI Blue Plus
• 2 ATI Coral Plus
• 1 ATI Purple Plus

I've since switched out the Coral Plus for two more Blue Plus thinking maybe less "white" light would help. Not sure it's going to make much of a difference though.

Does anyone have any thoughts or ideas? This one has me puzzled...

 

[glb]

The temp is the same in the smaller tank? It should be but I thought I’d ask.

 

[Kann]

Yep - same temp. The lighting is the only thing I can think of that's different but I wonder about that too given the low phosphate and nitrate levels I have.

 

[cincyfishguy]

Whats the stock list? Maybe your fish are keeping it clean?

 

[Kann]

Whats the stock list? Maybe your fish are keeping it clean?

I wondered about that myself. I have a few tangs and a bunch of snails and crabs in the 210 that are surely helping keeping it clean. I've moved a lot of snails and crabs to the frag tang as there just isn't much in the display tank to feed that many critters.

In the frag tank I have a bristle tooth tang, and a TON of small snails and crabs. Seem like just more algae than the CUC can handle.

 

[mcarroll]

Yup, I agree with most....differences in light, flow (between tanks and within each tank), nutrients, feeding and CUC would be what I'd look at.

Have you measured nutrients from all three tanks at the same time? You might (or not) be surprised at how different each tank is.

 

[Kann]

Have you measured nutrients from all three tanks at the same time? You might (or not) be surprised at how different each tank is.

I wondered about different phosphate and nitrate readings in the frag tank too, but when I tested them they were identical to the main tank - undetectable. It HAS to be lighting. That’s the only thing I can come up with anyway...

 

[mcarroll]

You feed both tanks the same and both have the same flow?

Get yourself a lux meter app on your phone to check the lights, BTW. A handheld meter is even better...check this out: Beginner’s Lux

 

[Kann]

You feed both tanks the same and both have the same flow?

Get yourself a lux meter app on your phone to check the lights, BTW. A handheld meter is even better...check this out: Beginner’s Lux

Honestly, I’d say I feed the frag tank less than the main display tank and that the frag tank has more flow. Strange, huh? I don’t get it...

Our local reef club has a nice par meter that we can check out. I’m going to try to get the meter this weekend and rake some measurements.

 

[mcarroll]

Not that strange since flow corresponds with nutrient availability as well as waste removal.

If it turns out to have similar or more light then you have a pretty complete formula.

An app on your phone would get you an answer tonight. Comparing with the PAR meter later will be interesting.

How does coraline algae seem to do around the system? e.g. Better in one place than others?

 

[Jlentz]

I’d guess it’s a fish stocking difference. I’ve got two 90s plumbed together. Same deal. Sps reef is spotless. It’s got a yellow, purple, and dory tang.

Lps reef is overrun with GHA. The peacock shrimp will only suffer a useless lawnmower blenny and a single yellowtail damsel to live. I try to keep up with hermits and snails but they can disappear fairly quickly.

My last shrimp in this tank was really chill. Didn’t give a dang about fish. I had a small school of tiny yellow tangs at one point and the tank was spotless.

Light spectrum in lps/mantis tank is fairly low and tilted heavily to the actinic end of the spectrum to help simulate deeper water so I doubt it’s a lighting thing.


Also running a turbo ATS in the shared sump.