Help!? bubbles everywhere

[purp]

I just changed the lighting over my 75 gallon tank to 2-250w metal halides. they are 10K single ended not sure of who made them, before just 4 VHOs. It was a fish only for over a year, I traded most of the fish for small coral.

I did a lot of reading and started the halides for a few hours a day slowly raising to 8 hours over a few weeks, but now all of my sandbed and rocks are full of bubbles, a lot of them. Looks like a pan starting to boil. The sandbed is not deep only an inch or two in most places. What's going on?? When the halides are off they go away but come back after only a few hours the next day.

PS no sulfer smell when they reach the top.

[Reptoreef]

Sounds like you have algae or cyano that is utilizing the light to take in co2 and in return, release oxygen. Tell us more of your system(equipement, water source, etc).

Repto

[purp]

It's nothing fancy, just a 75g AGA, with a small sump and regium, a couple of maxi 900 powerheads, 50# LR that has been in the tank for like two years. I have not seen any cyano for over a year now and no hair algea or anything, tang makes sure of that. But the bubbles are driving me crazy. Only time I saw this before is when cycle the first time and was told it was nitorgen. Did the lights make a new cycle?

[Whoyah]

It sounds like your system is just adjusting to the increase in light IMO. It should slow down in week or so I would think. You are putting a ton more energy into the tank then before and your live sand is just out gassing the excess oxygen. A similar thing happened to me recently when I changed out my bulbs and added additional bulbs. Nothing to worry about.

And welcome aboard :D

[purp]

Thanks I think it is settling down now maybe 75% less bubbles than before.

[Whoyah]

Glad to hear it. Keep us updated.

[Reef_Angel]

Hey.... ours is doing that also since we put the new lights on the 180G. We have no build up of algae or cyano, just lots and lots of bubbles!! All in all, you don't think this will harm the corals in any way then? Dave just did a water change last night because it was due. The bubbles didn't go away. Good question Purp! You asked it for me too! Thanks! ....Angel

[JustDavidP]

The bubbles are most certainly a result of the change in lighting. They are a result of or a byproduct of increased photosynthetic activities caused by Auxotrophic algae and other stuff in the sand bed, rock etc. due to the higher intensity of your lights.

This is, for the most part, natural and non problematic. However, with that said, it is a reminder that until your system adjusts to the new lighting, that you should keep your nutrient load in check. The same changes that are peaking the Auxotrophic algaes and eventually your corals and coraline, will also cause changes and blooms in nusiance alga if fueled by nutrients.

I have a feeling that you will probably see a diatom bloom in your system shortly. If you do keep things in check, you could be spared from the blooms of cyano, hair algae etc. The diatoms are no big deal. They will eventually "burn themselves out".

If you do see cyano starting, or hair algae for that matter, you may want to reduce the photoperiod once again and start the acclimation over. Do it juuuust a bit slower this time.

Good luck!

D

[Reef_Angel]

Good advice! As a matter of fact, this morning is the first day I've seen it, but there is a slight blush on top of the sand this morning. Excellent heads up!!