Help with Alk/CA/pH... GARY!

[GaryP]

You're there on alkalinity and half way there with the calcium. The calcium is getting to the "acceptable" range. I would shoot for about 425.

[Richard]

I suppose the nutrient poor situation would also apply to those folks that advocate adding vodka or any of the other low molecular weight organic compounds.

Yes, although according RHF the people in europe that started the vodka thing say that vodka promotes different bacteria species than acetate. I've never seen any real study that identified exactly which bacteria species were responsible for nitrogen fixation and phosphate reduction so I don't know how they make the claim. I guess we are supposed to just accept that vodka bacteria are better than acetate bacteria because drinking vodka is better than drinking vinegar LOL.

[GaryP]

Well, bacteria are not that picky as to which carbon source they use. That have to be adaptable. The actual chemical difference between ethanol and acetate is almost insignificant from a microbiological standpoint.

CH3CH2OH (ethanol) vs. CH3COO (acetate).

All rapidly multiply bacteria are going to utilize available nitrogen and phosphate resources. The nitrogen is mainly used for proteins and nucleic acids (DNA & RNA) and the phosphates for making ATP (adenosine triphosphate). ATP is the molecule that organism use to store energy on a cellular level. Obviously, rapidly reproducing bacterial populations use more nutrients then do populations that are in equilibrium (reproduction equals death). I think the idea here is to create a bacterial bloom. When this happens, bacteria go into a logarthmic growth phase and their population rapidly shoots up. Some bacteria can divide every twenty minutes when there is plentiful nutrients available. That would mean that their population can increase by 8X within an hour and 64X in 2 hours. This rapid growth phase would suck the nutrients out of the water.

Obviously this sort of growth cannot be sustained without continued addition of nutrients. These nutrients would primarily consist of carbon source (ethanol, acetate, fish poop), nitrogen (ammonia, nitrate, fish poop), phosphates (ortho and meta phosphates), and oxygen.

I suppose my question is what happens after the carbon source is depleted. What happens to all thos bacteria? Some soft corals like Sarcophyton are thought to eat bacteria and I could see how that would be beneficial. My concern is that the bacterial population will crash, resulting in bacterial death and the nutrients that were used will simply be recycled back into the water as a result of decay.

BTW, I add a cap full of vinegar to my Turbo calcium dosing jug to help prevent it from reacting out with CO2 absorbed from the air. I have to clean it out occasionally because it gets nasty with bacteria growing in the jug and drip lines. I never had this problem before I started adding vinegar and it was just RO water and calcium. In that case there was no carbon source to support the bacteria. I suppose the vinegar also provides a small source of nitrogen and phosphates or my RO water isn't as pure as I thought it was. Only small amounts of phosphate are actually required. If I recall my bacterial ecology correctly, the ratio of required nitrogen to phosphurus is about 4:1.

[Bill S]

I had Richard check my water today:

Mg: 1140
Ca: 260 (I measured 220 yesterday - and have dosed about 25 teasp. of Dow Flake)
Alk: 3 meq/l

Until yesterday, I had neglected the Ca for about a week.

Richard is coming by on Tuesday to help me set up my Ca reactor.