Filtration on my FO

[pyramid]

I have a 75 gallon with 2 Aquaclear 50 PH's. A HOB Emperor 400 using 2/4 slots both carbon cartridges.
And about 15 pounds of LR. Of course a decent heater. And 6 damsels so far. I've been reading a lot and am confused as to what my next addition should be.
I'm thinking my Emp400 with the two large bio wheels should be doing great bio-filtration. No fish deaths for 6 months. As far as catching debris, it is so so. Should my other 2 cartridges be bio or carbon? Since I have two spots left.
Now do I need to immediately add more LR or should I go ahead and get a good skimmer? I'm looking to spend about 200 on a skimmer.
My LFS suggested I get about 15lbs more LR and CPR BakPak 2 or Fluval Fx5 with bio media.
I can't get everything due to budget constrains, but eventually I will. Also you guys think I have enough filtration now to get a Auriga Butterflyfish?
Thanks in advanced for help on my next step.

[leebca]

Regarding live rock, the quantity you 'need' depends on what you're using it for. A good discussion of the value of live rock is found here: What is Live Rock, Anyway?

Since you've chosen to setup a biological filter in your system rather than use the natural biological filter of the live rock, putting in more live rock should be avoided. The above link will explain why adding live rock in increments is not a good idea.

The capacity of any marine system to carry bio-load isn't directly related to the biological filter capacity. There are many other parameters. Besides the biological filter there are other bacteria there doing their own production of nitrogen wastes from left over organics. There is also the matter of maintenance. How often and what size of water changes are done; how often is the filter broken down and cleaned (making sure not to disturb the biological filter therein); how much detritus is building up in the system and how often is it removed; etc.; etc. Flow rates of the water is a consideration -- how fast will the poisons (ammonia, nitrites, etc.) get to the biological filter.

What isn't a factor is the number of fish deaths over time. I'm glad there have been no fish deaths over 6 months. But, there should never be any fish deaths at all, when the hobby is done properly.

So, since I don't know every filter and their capacity and flow, and I don't know the species and sizes of the fishes you now have I can't determine if you have sufficient biological filtration for this system. When flow is optimal; maintenance proper; care for fish at a high level; with excellent water quality, the current setup would most likely handle an Auriga.

I would urge you to setup and utilize a quarantine system: A Quarantine Process (step-by-step)

Good luck!

[pyramid]

I want to avoid more LR for my aggressive FO setup. After reading your link, I think LR is unpredictable
Also now I think my Emperor 400 (pumps 400gph) is a huge nitrate generator. Now I don't want to do more than 1 water change per week @ 20% each. I don't know if this will be enough nitrate filtration, once I get more fish. Right now I have 4 damsels. I have a couple powerheads running in the tank for circulation, from my UGF lol. I thought big bio-wheels and a UGF would be great for a FO setup. Now I'm thinking a good skimmer might be needed to lower nitrate levels, as this seems to be the weak point in my setup. Other options?

[leebca]

A skimmer affects nitrate levels only indirectly -- by removing organics before organisms turn it to nitrogen wastes (ammonia, nitrite, etc.). Size the skimmer properly as you'll read in this post: What is Water Quality. A skimmer isn't essential, but I would suggest all marine systems have one and one that is properly sized.

From the additional information, I would still say what I've posted at the end of my last post.

[pyramid]

Fluval FX5 &
Mega Powerful Nitrate and Phosphate Remover - DIY! - MonsterFishKeepers.com

Seems like a great combo.

[nicoledc109]

Regarding live rock, the quantity you 'need' depends on what you're using it for. A good discussion of the value of live rock is found here: What is Live Rock, Anyway?

Since you've chosen to setup a biological filter in your system rather than use the natural biological filter of the live rock, putting in more live rock should be avoided. The above link will explain why adding live rock in increments is not a good idea.

The capacity of any marine system to carry bio-load isn't directly related to the biological filter capacity. There are many other parameters. Besides the biological filter there are other bacteria there doing their own production of nitrogen wastes from left over organics. There is also the matter of maintenance. How often and what size of water changes are done; how often is the filter broken down and cleaned (making sure not to disturb the biological filter therein); how much detritus is building up in the system and how often is it removed; etc.; etc. Flow rates of the water is a consideration -- how fast will the poisons (ammonia, nitrites, etc.) get to the biological filter.

What isn't a factor is the number of fish deaths over time. I'm glad there have been no fish deaths over 6 months. But, there should never be any fish deaths at all, when the hobby is done properly.

So, since I don't know every filter and their capacity and flow, and I don't know the species and sizes of the fishes you now have I can't determine if you have sufficient biological filtration for this system. When flow is optimal; maintenance proper; care for fish at a high level; with excellent water quality, the current setup would most likely handle an Auriga.

I would urge you to setup and utilize a quarantine system: A Quarantine Process (step-by-step)

Good luck!

Thank you for the information