Tank Hit With Diatomic Algae

[Matty P]

Our 122g reef tank was hit with Diatomic Algae last week and has gone from this...

to this...

Lost hunrdeds of £££ of livestock - all the corals, and have only 4 fish left

Before:
1x Male Bartlett's Anthias (Pseudanthias bartlettorum)
4x Female Bartlett's Anthias (Pseudanthias bartlettorum)
2x Ocellaris Clown (Amphiprion ocellaris)
1x Blue Star Leopard Wrasse (Macropharyngodon bipartitus)
3x Banana Wrasse (Helichoeres chrysus)
1x Fridmani Dottyback (Pseudochromis fridmani)
1x Red Sea Cleaner Wrasse (Larabicus quadrilineatus)
1x Atlantic Blue Tang (Acanthurus coeruleus)
1x Coral Beauty (Centropyge bispinosus)
1x Lamarks's Angel (Genicanthus lamarck)
2x Regal Tang (Paracanthurus hepatus)
1x Chalk Goby (Valenciennea sexguttata)
5x Blue/Green Chromis (Chromis viridis)

After:
1x Blue Star Leopard Wrasse (Macropharyngodon bipartitus)
2x Banana Wrasse (Helichoeres chrysus)
1x Blue/Green Chromis (Chromis viridis)


I think it has come from the R/O Unit requiring new filters, they have been needing changed for a while and we have left it too late. Possible silcates and phosphates have got into the system because they weren't completely removed from the "tired" R/O filters.

I have replaced the phosphate remover (Rowaphos), and are getting someone out to replace all the filters on the R/O Unit.

Any other ideas to remove any causes of the diatoms?

 

[Lynden]

In case you weren't previously aware diatoms did not kill those animals. I would say it is something left in the water, possibly fluoride. These chemicals can cause a breakdown of nitrogen processing bacteria, leading to a loss of "cycle". I would call this the most likely occurrence. If so, replacing your RO filter should cut it, and perhaps the addition of a commercial water conditioner could help as well.

 

[Matty P]

OK thanks Lynden, I won't be adding any more livestock until I have it cleared anyway

 

[jeasko]

may also be worth once the filters have been replaced doing a large water change just to kick start the removal process

 

[Matty P]

How much do you think I should change? I have been doing about 20% every couple of days, but that doesn't really mean anything beacuse if it is silicates causing the problem then I will just be putting more in by doing water changes.

 

[dilbert]

I had always the impression that only around 20% of the silicates are removed by an RO unit. Only DI water shouldn't have any silicates.

Also, I guess that the usual diatoms outbreaks in new tanks stem from the sand that has been brought in.

So, I would think that silicates haven't been the cause of the outbreak and wouldn't be a problem now.

I would say it is something left in the water, possibly fluoride.

Is there a way to measure such fluoride, directly or indirectly?

 

[Lynden]

Not that I know of. Pool test kits may have one; also the offending chemical is not necessarily fluoride.

 

[SkiFletch]

Agreed, could be Chlorine, Chloramine, Bromine, or Ammonia as well as others. Tank crashes are often the product of a single small contaminant killing something releasing more decay/toxins which in turn kills more tankmates, and ultimately overwhelming/killing the biological filter. Ammonia then sweeps in and takes hold, finishing off the rest of the animals, only a few hardy individuals sometimes remain.

Recovering from a crash, first test for nitrogenous products (ammonia, nitrite, nitrate) to see if your biological filter is funcitoning and handling the dieoff. I'd run HEAVY carbon for a week to make sure you remove any toxins that you can't test for. During that week, I'd prepare enough water for a 100% waterchange. Yes, I said 100%. If the offending toxin is something you can't remove with carbon, you don't want it in your tank. The fish will be OK so long as the temp/salinity remains the same and you start re-filing quickly after epmtying the last bit of water.

As an FYI, that is NOT diatom algae, that's a species of cyanobacteria. Very common after tank crashes, and another good reason to 100% waterchange

 

[Lynden]

Actually taking a second look it does look a little like cyano... the colour is off though in my opinion, having had both a-plenty. My first explanation does however still apply here... competitors were killed off.

 

[craigybaby37]

this is so savage to see. sorry to hear about it hope you get things up and running again soon.