Greeeeeen water in HUGE tank

[ladyfsu]

OK...here's the deal. Last year a marine bio teacher at the school built this outside tank. It is approx. 2 ft high, 5 ft wide, and 12 ft long. It was to be used to grow mangrove seedlings and keep some of the fish we find here in the estuaries (pin fish, sheepshead, etc). Well, some DISASTEROUS things happened during the year. Let's put it this way...I have been put in charge of the program and it is starting from scratch but going well.

My next project this summer is to get that tank operational. With absolutely NO CARE for a year, most of the mangroves have managed to grow fairly well and every once in a while I see there a fish or two come up to eat off the top (it appears to be a pinfish). There are a few crabs alive in there somehow too.

We are trying to get this stupid fluidizer filter to work for it but so far, not so good. The water is a dark disgusting green. Besides a semi-large water change, what other things can I do to clean up this water (no, I'm not going to empty it and start over).

I'm really asking....what kind of organisms REALLY like to eat LOTS of algae? Do you think I can put 2-3 large sea hares in there to start the cleaning it up? Conchs? Large salt water catfish? I am hoping to have it at least 50% cleaner by the time school starts in August. Thanks.

[fittdog8848]

Snails, crabs, seahares, and alot of manual removal are some of your options here. I am not sure that you will be able to get this tank looking clear for school time.

I would start with water chagne and get a filter on the thing.

Does this big tnak have any kind of skimmer?

If not setup a water change schedule and have some students run that part.

Without skimming or scheduled water changes I do not see it getting better.


Good luck to you

[Bebo77]

you can use carbon and a diatom filter....

[theop]

Tanks that get natural sunlight commonly get that green water. It is in both freshwater and marine setups.

I don't know of anything that will eat algae out of the water column. Also, carbon won't remove algae.

Your best option would be either:
1. A fine diatom filter to strain out the algae. The main limitation here is that if you run the filter all the time it will need cleaning frequently.

2. Get a UV sterilizer. This will kill the algae and prevent these algae blooms. Figure out the approximate volume of your tank and buy one rated for that size. You'd be looking at ones designed for ponds, so make sure you get one that is ok for salt water use. This would be the way I would go and will probably be cheaper than an appropriate-sized diatom filter.

Why are you trying to use a fluidized bed filter? Those are notoriously unreliable and I wouldn't even think of using one for an outdoor tank.

[MegaPods]

I reccomend a Very large sump as your filtration on something that big

[idratherbediving]

Yes a UV sterilizer is a must also if it is in full direct sun try to block some of the sunlight from getting to the water. Maybe with a tarp or a trellis of some type. The more sunlight the more green water you are going to get.

[ladyfsu]

Thanks all!

Idratherbediving -- yes there is tarp over it.

THEOP - I am using the fluidizer because that's what the guy from last year had. Most things we have are donations and so we use what we have. This thing is rated for 900 gallons but...it doesn't work so I'll be re-thinking this whole thing (sounds like car wash fund raising time).

fittdog8848 - Yes, I will be having students do regular water changes.

The diatom filter...someone DID donate a big box of this powder but I don't know what the heck to do with it, and I'm thinking it is really really old.

I think I'll be going to the beach tomorrow to find LOTS of snails and maybe 100 gallons of natural sea water. I'm thinking about this now...I think he just used the hose with dechlorinator to fill it up and that might not be so great, huh?

I've got one heck of a job ahead of me (and I'm looking forward to it ).

[idratherbediving]

I have 2 koy pond setups 1 about 10,000 gal the other consisting of 3 smaller ponds probably 2,000 gal each. The larger pond has a sand filter and a Jacuzzi pump run on high that goes to a waterfall and last year I added a vu sterilizer. I have been struggling with green water for about 8 years with this system, the sterilizer helped some but didn’t solve the problem. The 3-pond system is connected by 2 streams about 100 feet long. The streams are 18�-24� wide by 6�-8� deep with 2� of ½� round gravel in the bottom in a pond liner run by a 2300 gal per hr pump. I have never had a problem with green water in this system it has always been crystal clear. Both systems are in full sunlight.
I don’t know if it would work with salt water but if you could create a stream 30-50 feet either above or below your existing tank with a small pond at least 100 gal for the circulation that may solve the problem. You will have to top off the water more often because of the increased surface area.
Do you have any pictures of the sight?

[ladyfsu]

I've never done this before, but I took a little video with my digital camera. It takes about 1 minute to d/l but the video is only about 30 secs long. We were able to get the filter working...we'll see if it helps. Tomorrow I'm going to do a 60 gallon water change AND if time permits, I'm going to drive to the beach and get another 50 gallons of sea water.

I've never done this video and web thing before...hope it works :/

tank video

[adnup]

Originally posted by ladyfsu
I've never done this before, but I took a little video with my digital camera. It takes about 1 minute to d/l but the video is only about 30 secs long. We were able to get the filter working...we'll see if it helps. Tomorrow I'm going to do a 60 gallon water change AND if time permits, I'm going to drive to the beach and get another 50 gallons of sea water.

I've never done this video and web thing before...hope it works :/

tank video

DONT get your water from the beach. You need to go out around 7 miles to get good clean water. The water close to shore around here ususally will have "junk" in it.

Well after thinking it over it still may be better than whjats in there already.....

[theop]

The fluidized bed filter will only help convert ammonia -> nitrite -> nitrate. It won't do anything for your green water. It provides a high surface area for aerobic bacteria and fundamentally is no different from any other biological filter media like bio-balls or floss.

I doubt you have either ammonia or nitrite with only a couple of fish. That filter is a good solution for biological filtration, but I think you'll still need increased mechanical filtration and UV to get the water clear.

[kevensquint]

Since you don't have money and your water obviously has tons of nitrates, phosphates etc.. I would get a couple of 100 gallon strong rubbermaid bins, fill them with sand and use them as 2 really big remote DSB buckets. It will cost you a few plastic bins and a small pump or 2, you can easily make a DYI overflow to feed water to the bins with PVC pipes. If you use sand from a beach its free. So the cost would be very low. Within a few months this should help bring down nitrates and phos. But, your still gonna need some other sort of filter to remove particles and waste. Maybe a pool place can hook you up with a used pool filter? or donate one.

[ladyfsu]

ADNUP - hey friend....yeah, the water at the beach will be better than what's in the tank.

Did anyone see that big 30 gallon or so tub at the back? It's black. You think I can make that into a fuge? I'm not trying to grow nice corals or anything...we just want some of our local critters to live in this thing...and some of the guys around here live quite well in polluted water (no not great, but you know what I mean...some fish are very very hardy). We want to put a couple of sheepshead, baby snook maybe (yes i have the license for undersized), pinfish, grunt, little snapper etc in there.


BTW ... can you guys see the video? I've never done that before. If it works, I'll be using it in class to show student work, etc (making live rock etc).

[Agu]

I think you need to invite the members of your local clubs to come over for the afternoon, look over the situation, and get some hands on help/advice.


But that's just because I want to see this tank .

[ladyfsu]

LOL HEY ADNUP!! Yes, I think that would be good...well, GREAT !!! THANKS!!!!

OK, give me the weekend. I'm going to take pics of all the tanks we have and all the donated equiptment and put them on my site. That way maybe we can brainstorm before people get there. We also know the founders of Hooters so we'll go beg them for some wings for the day (I LOVE Hooters except for them dang Hooters ) !

[ladyfsu]

KEVIN...sorry you posted at about the same time I did and I missed what you said. We actually have a pool filter I believe that was donated. What you were saying is exactly what I was hoping to hear!!! Hmmm...trial and error and learning...isn't that science? I think I'm going to work on what you said. I've read the GARF articles and some others. I think DSB and fuge's can do what I need withOUT the need for expensive skimmers and UV lights etc.

I'll post up when things start going into action and I can tell you guys what is happening (good or bad...fingers crossed)!

Thanks all!

[kevensquint]

Look up DSB in a bucket by A.Calfo, because there is not much to know, but if you do it blindly you may end up with a nutrient sink making things worse. I know from exp. that a DSB bucket can work and according to A.Calfo's article on them he used a 55 gallon tank full of sand to bring down nitrates in a 1500 gallon system. So just upsize the DSB bucket to handle your big tank. But do read the articles first.

[ladyfsu]

Originally posted by ladyfsu
LOL HEY ADNUP!! Yes, I think that would be good...well, GREAT !!! THANKS!!!!

Ooops...Agu...wrote Adnup's name again by mistake and not yours...sorry! That's what happens when: Miller Lite + Devil Rays Game + 3 kids + reading forums. Eeks...plz forgive! I love your idea and I'll be posting something up soon.

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