Bob is right in as much as surface agitation is responsible for gas exchange. What Bob is wrong about is that all those bubbles that "don't matter", have surfaces, and that is where a large percentage of exchange takes place.
Deb et al., I am not sure why you continue to try and educate Bob. He has made it plain and clear for the last year that he is going to do things his way. I see no point trying to force a point like gas exchange. You do your thing, and Bob can exchange his gas anyway he sees fit. Please help the people that ask for help, for the are the ones that appreciate the effort. You all give really good advice, so give it to people that want it...

I'm all for passing gas at anytime. :lol:

Meanwhile, back in the oasis... 8)

True but it also happens in other places.

totaly bogus.. like Brad said the more bubbles the more surface area. this is why the beckets were made.. to increas O2 levels in ponds to promote healthy ponds. what you are probably thinking of is thoes bubble walls .. compared to Vigerous surface agatation the only help a little.. compared to nighting.. they help a lot. with the small surface area of a becket you actualy have a very efficient method of adding O2 to a tank.. my tank has barly any surface agatation now and I have lots of O2.


Providing it is well ararated no it shoulden't.. BUT in a new 20 gal tank with agressively growing algae and such the )2 level can be depleted at NIGHT time.. this is why you have to make sure your surrface agatation is high at night also (or run a skimmer).


Good, that must make you happy.. mind you I hate it when fish hide :wink:

Steve

The point is that I have kept fish for about 40 years, and have read numerous books. During all that time it has been my understanding that bubbles pumped into water do not increase oxygen levels. It is always possible that all those authors were wrong, or there has been more recent information. :wink: :wink:

I did expect to get yelled at for posting what I feel was correct information. :D :D

However, very shortly after my last post the fish was doing circles on the bottom of the tank. He was not gasping, but merely quickly dying. It appears that I should take my own advice, and not purchase recently arrived fish. It is just so wretchedly hard to get a Royal Grama. Maybe next time I will take Doug with me, he was smart enough not to buy. :(

BTW, that tank has a Maxijet 400 blowing toward the surface, and a Hagen 301. Lots of surface agitation, and circulation. 8)

[quote="Alan Joseph"]Sorry I misunderstood. I thought you had the Six Line, and the Grama for only a week before they died. :?:

In my defense, I have mentioned a number of times that I had a number of very expensive losses when I fist set up a SW tank. Those losses stopped when the tank was six months old, and I put in a bunch of live rock.

I suppose the problem is that a person cannot wait that long before adding some livestock. :(

.



I am sorry for not providing enough information. There is no way you could have known that YES the tank was new, but the contents were not. The contents were everything out of my 10 gallon nano, with a number of gallons of water out of the 50. In other words it could be called an existing tank with the addition of some substrate. :oops:

Well when I run my skimmer my ph is day 8.2 / night 8.1
When I do not have my skimmer on my ph is day 8.1/ night 8.0

I believe this proves that they do add oxygen to the tank becasue the obvious result here. I do also have an overflow and lots of other opportunities for air to be added to the system. The skimmer just top's it off.

I'm confused
 

So I buy this 180 gallon tank add sand and let it run for two weeks in fresh water to make sure everything is ok (doing 2 complete water changes), then I add salt. I ask for advise on cycling a tank ...which fish...and the advise I get is use live rock/sand. So I buy 25 pounds of live sand, and 40 pounds of live rock and add it to the tank and wait for 6 more weeks (longer for the refugium) and do bi-weekly tests. The tank goes through the ammonium cycle, the nitrite cycle, and the nitrate cycle (mostly...it is now stable). Then I ask for opinions on first fish. (here and on other forums).

Well I get this mixed message. Firstly to calculate the tank loading It is 3“ of fish per SF surface area, but no more than 25% of that while cycling a tank. Also in damsel population add 1, 3, or 5 or more and not even amounts (this from more than 1 source) and also to add all of 1 species at a time. So I take my girl to the per store and we pick out 5 damsel fish and 2 chromis (all very small < 3/4")… from the same tank and a new shipment. Given that I have 180 gallons in the main tank, 33 in the refugium a 40 gallon sump and I am skimming, that seems like a very reasonable amount of fish to start doesn’t it?

Re: I'm confused
 

I tend to agree. For all intents and purposes you should have been fine, but, and this is a big but, it has happened before. For that reason everyone advises caution. With 250 gallons of water, and a few little fish there should be no problem. It is a mystery to me. I did this on a smaller scale. I set up a 50 gallon tank some years ago, ran it through the cycle, and added fish one at a time. The fish all got horrible diseases and died (except for one, he died three years later) For that reason I advocate the six month idea, but in reality who can look at an empty tank for six months?

I would add however, that the Damsels should not have died, as people have used them to cycle tanks forever. There must have been something wrong with them when you bought them. :(