Keeping up Ca, Mg and str.

[Ace25]

Thanks for that link Aeros. Very informative. I thought I had gone through every AA and RK article since their inception but the one you linked to didn't sound familiar to me. Either I read it really early on in my reefing days and didn't understand it, or missed it, but today that is a treasure trove of good information on that subject (heavy metals in the aquaria).

Can anyone explain to me how a CA reactor can raise alk so high it crashes a tank, but still leave calcium levels a little lacking? I have a friend with a 240G tank and 6 months ago he switched from dosing to a CA reactor, worked great for 5 months. pH is set right on the effluent. CA last week was 360 and Alk was over 14 and all his SPS corals died. He went from an Alk of 5 to over 14 in less than a week, didn't make any changes at all to his system, all of the sudden he got a huge alk spike. I have no clue how to to explain it (I admit, I have never used or setup a CA reactor myself, only seen them in action on other peoples tanks), which is why I am asking the question.

[kerry]

Here is a good article I though I would share about adding vinegar to your Kalk solutions. http://www.reefscapes.net/articles/b...alkwasser.html

[Floyd R Turbo]

That is the perfect article for me. I need to understand the chemistry behind such a method. Thanks for posting that!

One thing that I thought of when reading this article, is that there is a discussion on the availability of CO2 being a major factor, and that low CO2 can cause the Cal and Alk to actually drop when dripping kalk directly into a system. I wonder if there is any concern here w/r to scrubbers, since the algae pulls CO2 out of the water, would that tend to create a low CO2 situation? I guess it would depend on a few other factors related to gas exchange. On the tank I run a scrubber on, it's rimless but in a cabinet so it's not quite 'closed' and still evap is upwards of 2g/day on a 144 (actually 110 total water volume)

[Ace25]

It is too early for my brain to work right... but what does it say when adding a fan over the ATS screen gives you alot more growth? Does that mean the tank is O2 limited or CO2 limited? Whatever the answer is to that I think would answer your question Floyd, although every tank is different so results may not be the same for everyone. Also the tank I put the fan on is also the tank I top off with Kalk, which may be the reason the fan helps so much.

I don't run a fan now, but on my 75G I still get close 2G a day in evaporation, with a fan it could be 3-4G a day on my system. I have dosed full kalk for longer than I have been running an ATS on that tank, my 60G I don't dose kalk, just 2 part, although one ATS uses LEDs, the other uses CFLs, so it is really hard to compare them to each other because the CFL scrubber only works about 20% as good as what my LED scrubber seems to do (going just off growth of algae). The LED scrubber tank runs with Kalk top offs.

[Floyd R Turbo]

gas exchange happens in both directions, so I'm of the opinion that with a tank that is evaporating 2g/day, that indicates you have no problem with gas exchange. That means if you water CO2 level drops, it will pull it out of ambient air in order to attempt to achieve equilibrium, same with O2. I maintain another (non-scrubber) tank that has glass lids and it evaps maybe 0.5g/day and the pH is always much lower (even when it had a skimmer)

[Ace25]

That sounds reasonable to me, if you have that much evap then gas exchange shouldn't be an issue.

Skimmers provide aeration, not oxygenation, so that makes sense the pH could be lower on that system you describe. If the skimmer is in a closed stand where there is little airflow, the aeration part isn't really able to do much, where as with a scrubber you get oxygenation which will raise/stabilize pH. If you have good airflow around the skimmer I would think aeration would work much better than in a closed stand (just a general statement, not sure if that pertains to your setup).

I think of aeration as simply "the ability to perform gas exchange" but if you don't have good airflow around it then good gas exchange may not happen. Oxygenation forces O2 back into the water, it doesn't rely on passive exchange like aeration does.

[Floyd R Turbo]

yep, same deal with winter home syndrome. We have local reefers here in Iowa who run the air intake line for their skimmer through to outside air during the winter and it gives the pH a nice boost over using the stagnant inside air. And you described that low-pH system exactly, skimmer in a cabinet, pH never really went much over 7.8 which isn't really that low, but had no corals so who cares.

[kerry]

Not sure if this is as good as MRS. Wages but, here is a product I have found and ordered. I am sure its got to be suitable. http://www.healthypets.com/kalkwasser1lb.html

[kerry]

It looks like most people mix a teaspoon of this with a liter, quart or gallon of water (and some mix in a few ml of vinegar). Does anyone know how much this would raise the CA in a certain amount of water, like how much would one teaspoon raise CA in a 50G or 100G tank?

[Ace25]

Very expensive Kalk there.. you can get 4.5x more from BRS for the same price.

http://www.bulkreefsupply.com/store/...aquariums.html

I mix 30 grams of Kalk with 5G of RO/DI water. I bought one of those 4.5lb containers over 5 years ago.. still over 1/2 full today. Stuff lasts forever.