Color and growth talk - clean vs dirty tank

[gws3]

I have paid particular attention to this subject as I lost a lot of corals over a few years due to what I believe was coral starvation resulting from GFO use.  I have also had discussions on this matter with a few individuals who I consider very successful and knowledgeable with this hobby.  Overall I would conclude:

 

Higher Nutrients = Deep rich colors = long polyps & thick coral tissue = slower gowth = more tolerant of higher light = more tolerant of increased alk levels (9-11 dKh)

 

Lower Nutrients = Paler colors = smaller polyps & thin coral tissue = faster growth = less tolerant of higher light = less tolerant of increased alk (better to keep alk 7-9 dKh)

 

 

One very important thing to note is that low NO3 and PO4 numbers don't always mean low nutrients..

 

For example:

 

If you have high nutrient input and high nutrient export, you likely have nutrients available to corals, but the tests may read 0.

 

If you have high nutrient input and low nutrient export, you likely have a tank full or algae and tests read 0, or you have a lot of tangs/snails/shrimps and test kits read high levels.

 

If you have low nutrient input and high nutrient export, you likely have little algae, pale corals that grow fast and then STN/RTN.

 

 

I think just like with Alkalinity, nutrient stability is important.  Corals likely spend a lot of energy maintaining an appropriate level of zooxanthellae.  If your input/export of nutrients it constantly changing your corals will likely suffer.  Of course if corals are down right starving they need food and a change is necessary. 

 

 

Gone are the days when it was confidently believed NO3=0 and PO4=0 is a good thing.  The pendulum has swung the other way.  It's only a good thing if you have enough nutrient input to keep corals healthy. 

 

 

I am (now) a strong believer in keeping things as simple as possible and as natural as possible.  I don't run any GFO or GAC any more.  I tried dosing NO3 and PO4 (yes, I have dosed phosphate) with some benefit.  But I think you should only dose either to get them in balance.  If levels are low feed more.  Feeding is a balanced NO3/PO4 additive I believe.   If levels are high and it's an issue (algae growth, dark brown corals) export more. 

 

 

I use a strong skimmer and Algae Turf Scrubbers for nutrient export.  I also keep powerheads in sumps to keep detritus stirred up.  I run filter socks.  I do 5% weekly water changes.  When I first started feeding more I got a lot of nuisance algae, this approach has let me reduce nutrient algae while keeping corals from starving.

 

Now that my herbivores are keeping up with algae growth and corals and coralline are out competing these lower forms I plan to dial back the ATS on time.  Currently my NO3 and PO4 numbers will linger around or slightly above 0.  My corals are not starving though. 

 

I would like to get my system to around 0.5-2.5 ppm NO3 and .03-.08 ppm PO4.  Not that I think these are ideal values, the flux of nutrients is more important.  But the problem with 0 NO3 and 0 PO4 is that I do not know if export is exceeding input, and corals will start starving.  If I can maintain readable values, then I know my import/export is balanced. 

 

I have found montis and zoas to be fast indicators of nutrient issues.  If zoas are small and grow slow I need to feed more.  Montis react quicker than acros and recover faster.  I think acros can have a slow reaction and then RTN/STN fast.  They will also RTN/STN long after a nutrient issue is addressed, where as a monti seems to show a quicker reaction to a positive change. 

 

For me fixing my nutrient issue has been much slower than I would prefer, like turning a ship.  But feeding more in the long run resolved pale colors and coral loss.  Upping nutrient export, sticking to a feeding schedule and increasing herbivores has let me get ahead of algae.  Now I just need to fine tune the system and keep it stable.  I think the stability will enable good growth with the best colors from the nutrients being available to the corals.  I'll stop rambling now. 

[Anemone]

Really liked this sentence: "If I can maintain readable values, then I know my import/export is balanced." Seems very good to keep this in mind, else your starving corals may start digesting themselves.

[gmerek2]

Based on my experience it's 1)fight algae and have excellent color or 2)have decent color with a cleaner tank. I prefer #2 the herbivore thing works until some nasty stuff rolls in that nothing will touch

[Der ABT]

Great discussion

 

I think stability is the key to all......when my tank was at is best I had alot of aptaisia etc....but parameters were rock solid.. blasted corals with lights and flow in the Main and went leds on the frag tank and had the same colors just had some missing color and polyps where the leds were causing shaded areas....growth was definately slower under the leds.....but colors were very similar with the full spectrum d120s.

 

I always had trouble with zoas unless I had sand somewhere in the system.....fuge or just a Tupperware in the frag tank.

 

Sps just grew and grew in my 156 even with aefw and crazy algea......and that was diiiirty....had echinatas, smooth skins and other not so hardy sps doin fine and couldn't explain it

 

Again it's more with consistency to me.

 

But I think halides do play a large part in keeping happy sps....they color all the way around the branches etc even in less than ideal conditions.....I think leds have come a long way so this may be changing.

 

Also the post about the balance of import export may be my favorite so far as its often overlooked when setting up a system

[yauger]

great post GWS3