Re-starting up tank - some questions

[Natterjak]

We had our 70-gallon tank up and running for a few months before an infestation of cirolanid isopod hitchhikers forced us to leave the tank fallow for 6 months or so. In that time, all we've had are a handful of snails and hermit crabs. We didn't do water changes, just kept it topped off, which unfortunately led to a bad outbreak of algae and cyano in the sand and tank.

We have about 70 pounds of live rock and 60 pounds of live sand. Right now we're running a wet dry with a HOB overflow - my first question is whether or not I should remove all the bio balls and if I could then use it as a sump - do we have enough biological filtration in the tank?

Second question is, do I need to re-cycle the tank? Or would the bioload from the snails and crabs have been enough to sustain the bacteria?

Third, is there a good way to get rid of the algae/cyano in the sand?

Lastly, I had to change overflow boxes due to poor design of the old one. The old one came with a sponge filter/filter floss. The new one doesn't have this - do I need mechanical filtration somewhere?

Thanks!

 

[electrikat]

Live rock and a good skimmer are really all the filtration you should need. You will need a couple of power heads to get heavy circulation to get rid of the cyano. Yes get rid of the bio balls(they cause nitrate problems) and the filter will be a great sump with the addition of live rock rubble. You need a few heavy water changes but I wouldn't think you would need a full re cycling of the tank.

 

[BillyZ]

I would suppliment your LR just a little bit. typically you want 1.5-2 times your tank volume. get that in there, then, as electrikat suggested, do a big water change, I'd say about 20%, leave about a week and do another. and pull uut your bio balls slowly during this process (a few each day until they're all gone). The bioballs are doing some filtration so as you remove them you'll want the tank to recooperate the lost bacteria.

Whats happened to your tank is that there hasn't been any real fresh cleaning, so nitrates and extra nutrients have built up, providing a haven for the algaes and cyano. A little vigourus maintenance over the next couple of weeks with the addition of some more LR and you should be good to go. I don't see any reason a new cycle would start. (a cycle starts when there is an influx of waste production (fish added or large amounts of die off) without enough biological filtration to handle it. With your current LR and LS you have plenty of filtration.

another though, you might want to consider picking up a sandbed revitilizer. This is basically a bag of sand dwelling worms, pods and critters to be sure the sand bed is populated well and moving. you can get some from garf.org and a few other sites. Google is your friend!

Good luck and keep us posted!

 

[Natterjak]

Thanks for the replies.

I'm not sure how much more LR we can squeeze in there - our tank is tall rather than long, so I'm worried about a rockslide if we stack any more on top (if I add some to the sump, would I need to light the sump?) I hope we don't get any more cirolanid hitchhikers.

We've done about three 20-gallon water changes so far. So once I get the levels back to normal, I should be safe to start adding fish (slowly of course)?

We seem to have a pretty large pod population (they're all over the glass), and I've seen a lot of bristleworms and such in the sand, so I think our sand may be okay, although perhaps the algae growth suggests otherwise.

Thanks again for the suggestions.

 

[bound_for_obx]

Natterjak, I had the Cirolanid Isopods as well. Did you attempt the "CURE" for Red Acro Bugs treatment? I just went night diving after lights out and pulled them from the tank. It's probably been a few months since I have seen any.

 

[Natterjak]

I read about the cure, but never actually tried it. We lost all our fish (one to the isopods, the other two to an accident in our QT tank) and then just never got around to getting the meds from a vet.

We toyed with trying that, nuking the tank, or converting to FW, and the next thing we knew, 6 or so months had passed.

I'd caught one big one and pulled a smaller one off a fish, but I think a brood must have hatched, because we had a lot of little ones that were just impossible to catch. Everything I've read suggests that these guys should be dead by now with no fish to eat. I'm hoping that's true, and keeping my fingers crossed.

 

[electrikat]

Yes rock in the sump counts towards your poundage quantity. So does the rock rubble in your canister filter. You also do not need to pile it all at the back like a wall. Bring it out towards the front in a couple of places to make it look more natural. You can also use aquarium sealant or gel superglue to secure it better, but if you stack it right and don't put a bulldozer critter in there you should have no problems.