Took over a tank(s), need help

[Science Teacher]

New science teacher that took over 3 large salt water tanks. Had been working and fully functional, but derecho hit iowa, and we lost power for 15 days, and tanks went sideways. I took over position, and want to get tanks back up and running better. Has a lot of live rock, filter/pump system, and 3 fish that still live in first tank. (very large, about 10 ft by 4 ft high??)
Overgrown with kelp/seaweed. How to do I get that cleaned up? Just start pulling weeds out?

 

[albano]

That is a large tank! Like to know exact measurements.

I’d pull out as much algae as possible, and maybe a few rocks at a time. Clean those rocks up, then replace them and remove a couple more.

 

[Science Teacher]

That is a large tank! Like to know exact measurements.

I’d pull out as much algae as possible, and maybe a few rocks at a time. Clean those rocks up, then replace them and remove a couple more.

2nd tank. Would like to turn this one into a coral tank.

 

[noelskii]

Not sure how the tank looked before it lost power, but it looks like it can still be functional. Personally, I'd restart the tank from scratch. Remove all the rocks, scrub, dry and cure them... Clean the tank and everything attached to it... Good luck!

 

[shinylights]

New science teacher that took over 3 large salt water tanks. Had been working and fully functional, but derecho hit iowa, and we lost power for 15 days, and tanks went sideways. I took over position, and want to get tanks back up and running better. Has a lot of live rock, filter/pump system, and 3 fish that still live in first tank. (very large, about 10 ft by 4 ft high??)
Overgrown with kelp/seaweed. How to do I get that cleaned up? Just start pulling weeds out?View attachment 326578

Pull out as much algae as possible, do a water test as a large amount of algae usually means a excess amount of phosphate and nitrate and then depending on those levels you can tell what to do next.
I would personally do a large (40-50%) water change and then take out individual rocks and scrub them with a hydrogen peroxide dip, you can use a toothbrush or a course sponge. In the future, people usually grow Macroalgae (Chaeto, Dragonsbreath) in their sumps which will take out the nutrients that would otherwise grow nuisance algae in your display tank. You can also run large bags of chemipure to help get rid of phosphate. check to see if there are any dead organisms in the tank and take them out immediately, as they spike the nutrients in your water.

 

[Erics210]

Hello.
I think you may make it harder than needed by taking out the rocks.
Google Reef 3 Day Blackout.
You may be able to do longer since you do not have corals.
The suggestion of manually siphoning the water out and using your finger/thumb to pinch off alotbof the larger clumps of algae and do a water change is a great start.
Then do a 3 day blackout by covering the tank with black trash bags all around.
This will really help reduce the algaes.

The black out will just help kill the algae. It won’t remove the source of the algae which is probably high nitrates from the die off of the storm.
So after the 3 day blackout, I would suggest maybe do another smaller water change and siphon some more of the algae . Should come off easier after the blackout.
Next you MAY want to siphon 1/3 or 1/2 of the sand bed to remove collected detritus and waste caught in the sand.

If still really bad algae, consider another 3 day blackout.

Note: if you nitrates are in fact high(which will feed the algaes), the nitrates actually get absorbed into the rock.
Let’s say you have Nitrates of 50ppm.
Let’s also say you do an100% water change with nice fresh salt using an RODI filter system. If you don’t use RODI FILTER, (you may want to get, way better than dechlorinated tap water).
Anyway. Let’s say you do an100% water change. 10 minutes after you do the water change if you test nitrates will be like 5. But within hours Nitrates will leach back out of the rock and will balance between the rock and water column and end up somwwhere around 30,
So what I am saying is… Rome wasn’t built in a day. No quick fixes. You will need multiple water changes, manual siphoning, sand cleaning, and suggest blackout.

Another option is a sea hare which eats the algae like a lawnmower. But doing the above and then doing 20% water changes regularly till things are better should be a great start!!!