Bacteria bloom, how long till system is normal

[finrod2]

Need some advice. I have 240 that has had persistent NO and PO issues. NO was at 40 at one point but I couldn't get it down to under 20. I have a reef dynamics pellet reactor that just wasn't getting it done. I've heard the success here with vinegar dosing and began this about 3 weeks ago. All was well until this past Tuesday night when I can home from an overnight business trip. The inside of my tank glass was full of the cream colored bacteria that I've heard mentioned here. I cut off the vinegar dosing pump (BRS doser, I was dosing about 50ml/day which should have been ok).

My fish are ok, my mag anemone was stressed but now is getting closer to normal. I've been hoping to get NO and PO down so my SPS would be happy. With the bloom my NO is zero and PO is .04. My Alk is 12 so now my SPS are not happy. PH is 7.95-8.1. I've been using Reef crystals which I didn't realize was very high in Alk. I plan to switch back to Trop marin pro and do weekly water changes to slowly lower.

Questions:
Is there anything I need to do besides WC's to speed recovery?

How long will my skimmer continue to produce large amounts of foam? The foam doesn't get thick but pushes the lid off my Orca 250 skimmer!

Should I shut off my pellet reactor?

I plan to go back to dosing vinegar but start much slower.

[Southreef]

I'm certainly not the expert here but I will give it a shot.

As you know the ALK of 12 is pretty high even under normal circumstances. When carbon dosing, I keep my ALK in the vicinity of 7-8dKH.

How long were you running the bio-pellets? They do take some time (up to several months) to kick into gear to the point that you will start to see you No3 and Po4 decrease.

Anyhow, for immediate action items, I wouldn't necessarily stop dosing carbon cold turkey. I would cut your dose in half and continue to dose. If you stop the carbon altogether, your bacterial population will have a massive die-off which will send your nitrate and phosphate levels sky high. Water changes are always good and I would do it with a salt that is close to NSW levels. If you do a 10% water change with new water at a lower ALK it won't drastically bring your alkalinity down. Reference this article to help you calculate what size water change will have what effect on your current situation: http://www.reefkeeping.com/issues/2005-10/rhf/

I would also do a full test on your water parameters, the white particulate on your glass could also be from carbonate precipitating due to a lack of chemical balance. I think that based on your reported carbon dosing and skimmer activity, that you are most likely seeing a bacterial bloom, but it doesn't hurt to rule out other potential issues.

Finally, and perhaps most importantly, take a breath and relax for a second before making a ton of changes. I'm sure that in no time the reef chemistry rock stars will begin to chime in and help you rectify your issue. Good luck! :)

[finrod2]

Thanks Southreef. My big mistake was thinking that I was lowering Alk through waterchanges with Reef Crystals. I understood that I had to reduce ALK before my NO and PO go down to acceptable levels. I'll restart the dosing and low levels and monitor the tank. I have been doing weekly 15% (43G) to get lower. I didn't want to lower Alk that quickly.
Thanks

[bertoni]

I probably would siphon out as much of the bacteria as is easy to get, spending a few minutes at most. I'd probably cut back on the vinegar dose, but stopping it should be okay, as well. I don't think there's enough nutrients in the bacteria to cause a big spike if they die off.