It’s bedtime, but here are some more thoughts:
On water changes (for example) - a 100 gal main tank and 5 gallons per week change will only yeild a 5% reduction in NO4 & PO4 - that ain't much.....cause all the bad water values will only drop by 5%. . If your phosphates are .33ppm, they will only drop to .30 after a 5% w/c in 100 gal system…I do a 20 - 25% waterchange every 7-10 days - my bad water numbers will drop by 20-25%......If I skip a extra week, now I gotta do like 50% (50 gallons) to get back to the same values I want to get. OR I do 2 each 25 gal changes on consecutive days to get back down....I think some books suggest at least 10% a week and many books view 15-20% weekly as a baseline.....and that's when everything is "normal"!!!! When u get BAD water i.e. PO4 above .3ppm - NO4 higher than 30ppm, or ammonia above 1.0 it's gonna take 20% water changes daily to get that down - and that's AFTER we discover the reason things are so high to begin with. Also the new water going IN must be near zero (0) NO4/PO4/NH3 to get this effect. There are phosphate removing pads & solutions, but I cannot speak to their effectiveness, I don’t use them.
fish load versus tank size and setup:
it's really hard to have more than 10 inches, total fish length in a 100 gal volume tank (or 5" in 50 gal) (that’s every single fish in the tank, length added up to X) Especially if you have meat eating type fish......I do keep very high fish loadings, but i've also got refugiums, LOTS of cleanup crew in each tank, an average of 2000+ gph powerhead flow, 700 - 1000 gallon/hr filtration, about 1lb liverock per gallon, 4-6 watts HQI lighting per gallon, chillers on every tank, and lots of gravel substrate (on all 3 tanks with about 100 gal each) and it still gets challenging sometimes!
And MOST IMPORNTANT!!!
I’d NEVER EVER EVER add anything from someone else’s tank to my mains with fish in my tanks…..either pull the fish OUT and get them their own "bare bones" hotel tank for a while so any diseases/parasites that hitchhike in with the new clean up crew don’t make hosts of your fish….or quarantine ANY new arrivals for a month+ in their own tank prior to adding them to the main……Most large distributors of marine livestock have HUGE systems, interconnected and they are hotbeds for parasites/disease. Just cause you get clams & snails DOES NOT MEAN tiny fish borne problems are not present. Most fish illness & parasites are invisible to human eyes, till they show up in mass numbers on your fish and kill them in short order….. People loose more fish in stable systems cause a single drop of water from another contaminated system made it in, and brought with it LOTS of new problems. I speak from experience!! Quarantine everything or expect many new problems, some fatal to your fishes!!!
