Bioload Vs Inches Per Gallon Theory...

just make sure you dont blow a o-ring.

 

Stocking levels have nothing to do with filtration. What ever the levels of Amonia and nitrites produced, the bacteria will reproduce to handle. Bacteria don't care if they are in a Wet/Dry filter or floating in water. They will consume waste no matter what. The population will grow to the amount of available food.

Stocking levels are about disolved oxygen. Bottom line is, fresh water holds more oxygen than salt water. Period. Therefore, salt water stocking levels are lower than fresh water.

Salinity, altitude, and temperature all effect the saturation point of O2 in SW. My saturation point at 6000ft is less than sea level. My stocking level is lowered accordingly. Now with a good skimmer, you can oxygenate the water well, and flow and open tops all help gas exchange.....but that does not change the end saturation point of what the water can hold.

We have plenty of filtration to consume fish waste.... that does not change your fish being unhealthy because they are on the verge of suffocating. A large fish population can consume more oxygen that you can get in the water. Also, if your tank is overstocked, a power outage of 6 hours or more could kill your fish. That is what stocking limitations are about.

 

so how would a tank with a radiata lionfish, snowflake eel, and huma huma trigger hold out in a 55 gal? or a 30 gal with a clown, chromis, and firefish? just trying to help.

 

Well just understand..... under "normal" circumstances, we do fine. Unless the SW is real hot, real high salinity, or real high altitude, we still have enough of a saturation level to keep fish. With really good skimmers pulling a lot of air, really good tank turnover and open tops, we can exchange gas at a very good rate.

So say we have 10 tangs in a 55g. Well just sitting there, they would use up all the O2 and suffocate pretty fast. But now we put a bunch of air stones in and circulate the water well and really pumps some air in.... well they can live... until the power goes out.

So we have pretty good ways to have good exchange rates, and the O2 saturation point is plenty for just about all the systems out there.... so really, not too much to worry about. It's just that people mistake stocking levels with filtration limits.... it is about O2 levels and exchange rates.

If all you have is a HOB filter with glass tops and a power head, then you need to keep stocking moderate because you don't have a high exchange rate. If you have open tops and tons of flow and move a ton of air, then the stocking level can be high, just understand you migh get into low O2 levels if the power goes out or your skimmer takes a crap for a week.

Then obviously territory factors in and activity of your fish and proper filtration and water changes and what not all factor into how many fish a tank will support.

 

I always like to understock a bit anyway, esp seeing as marine fish have alot more personality than freshwater. Its almost like you don't need a whole load of fish to have something amazing to watch.

I think its more down to how much space each fish has like it has been stated. Cramped fish and fish who are constantly guarding their homes from other fish are going to be stressed and easily open to disease. If they are each allowed to find their own space, they are more likely to be healthy IMO

That and compability. Its not going to be nice for a clown to have a lionfish constantly trying to swallow it lol

 

there in seperate tanks, but that would be bad if that were the case!

 

One thing to expand on what Powerman said, the only thing with higher bioload is that you have more work getting rid of nitrates and phosphates. It's true that ammonia will be processed quite efficiently unless there is a huge spike in it but denitrification doesn't necessarily scale as well naturally in a tank because it mostly occurs in low oxygen areas which are much more limited than the oxygen-rich areas that the nitrifying bacteria inhabit.

Of course there are ways of dealing with more nitrates/phosphates, larger or more frequent water changes, larger refugiums, carbon dosing, adding deep sand beds, other types of denitrification methods etc. You just have to be prepared for the larger than normal bioload.

I also agree with what everyone else has said about oxygen and territoriality/aggression as well as taking into account the fish's natural behavior. A 6" eel needs much less swimming room than a 6" tang because the tang is a much stronger swimmer in nature.

It's all about finding a balance between all of these issues.

 

Very, very good point. I've never considered that.

 

Im pretty heavily stocked on fish myself... and like RedGambit I am having a small ph issue myself.

This has been running cross my head. Should we with our protien skimmers keep the air intake under the stand for our skimmer with doors closed on stand. or should there be a airtube running outside the stand for "fresh" air? And would this help with oxygen levels?

Sorry for going off topic a bit.

 

With my house closed up, my PH is low. Thought maybe I don't have enough air exchange in my closet. I ran a tube outside the closet, but it did not effect it one bit. I know of others that have good results running a line outside for fresh air, but it would not be easy for me.

I doubt you would see any difference moving your air. You stand is open in back right. If it is all closed up, I would give it a shot and see. Your skimmer is gassing off the top. If it is driving off CO2 inside your stand, perhaps the concentration is elevated inside.