Getting correct parameters to start putting in corals. Low alkalinity!

[WWIII]

200 gallon deep dimension, 320 gallon total system volume, rubbermaid sump, rubbermaid refugium (only live rock currently), aquamaxx coneS co-3 in sump skimmer, kessil a360we's and t5's, using regular Red Sea salt.

Parameters...
Salinity - 1.025
Temperature - 80.5
Nitrate - 16 ppm
Phosphate - 0.08 ppm
PH - 7.8
Calcium - 440 ppm
Alkalinity - 2.1 Meq/L 5.9 dkh
Magnesium - 1320 ppm

So the system has been up and running for 3 months. I have just a few fish and snails currently, moved over from my fowlr 90 gallon 2 weeks ago. Everyone is happy and healthy so far in their new home. My question is, how do I get my tank ready for coral? I want to keep a mixed reef, but leaning towards more sps. My alkalinity is what concerns me most right now. I have done 1 20% water change after cycle, and now 3 more 10% water changes the past 3 weeks. With the water changes I was mainly trying to get nitrates down since it's a new tank, however I was also hoping my alkalinity would come up as well. It hasn't seemed to move at all. I am using ro/di water mixed with regular red sea salt. The newly mixed saltwater tests to an alkalinity of 2.6 meq/L or 7.3 dkh.

So... do I keep doing water changes to try and get alkalinity up? Should i try to use a buffer of some sort or baking soda to raise it? Or do I need to look into kalk or 2 part already even though I have no coral yet? Any help/suggestions would be appreciated in order to get the tank ready for coral! Hopefully in the next month or so I can start to add some of the hardier corals I would like to include in my tank! Thanks!

 

[Breadman03]

Your alkalinity is ok as is. Look up Randy's 2 part recipe and you can make adjustments from the baking aisle.

Also, allow time between dosing calcium and alkalinity as they will precipitate if done together.

 

[WWIII]

Oh yea...

Just some other info on tank. I put in 150 lbs of dry rock from reefcleaners and have 1 inch sandbed using tropic eden reefflakes. I just used bottled ammonia, a little dr tims (for the heck of it) and a little live rock in the refugium to cycle the tank.

 

[slorichie]

i would use 2 part. look up the BRS(bulk reef supply) Calculator and info there on how to increase, amount and how much per day. You could use red seas pro salt for a few water changes to increase alk and will help lower nitrate. once you get the alk up use 2 part to maintain and make adjustments.

Richie

 

[bertoni]

Two-part is good over the long haul. I'd get the alkalinity back up to at least 7.0 dDK using some baking soda. I'd probably do that over 2-3 days. I'm not sure what the daily consumption rate might be, so you might need to dose a fair amount. I might start by adding around 1 dKH.

 

[WWIII]

Thanks for the help everyone! I think I will give the baking soda a shot since I have some new unopened on hand. Cooking 1 box of it (1 lb.) right now. Trying to do the calculations using the online calculators it looks like I will be safe in adding 1 lb of baked baking soda in my ato that currently has 20 gallons of pure rodi in it. That should take 3 to 4 days to be introduced due to evaporation and I will test each day to keep an eye on it. We'll see how it goes, I will keep doing 2 part research and look into getting a permanent setup for dosing.

 

[WWIII]

Ok so that worked... a little too well. After 16 hrs my dkh went from 5.9 dKH to 9.5 dKH. I guess good thing I don't have any coral in the tank yet, obviously I overdosed the system. When I used the online calculator it said for my system of 320 gallons to move dKH from 6 to 7 I needed 14.7 ounces of baked baking soda. So I cooked 1 lb. (16 ounces) and dissolved it in the rodi water that was left in my ato. In those 16 hrs I evaporated and replaced approximately 2 gallons of this baking soda saturated water. So now I'm at 9.5 dKH, which is ok, but I didn't want to adjust that fast. Now I filled the rest of my 50 gallon top off container with pure rodi water to dilute the baking soda. Hopefully that will be enough dilution to stop the fast rise in alkalinity. If it continues to go up I guess I will dump the baking soda solution and rodi down the drain and refill woth pure rodi. Then so a water change. I'm trying to match new saltwater which is mixing ro 7.3 dKH. Looks like it might take a while to get stable since I overdosed the system.

 

[bertoni]

Well, as long as the corals are okay now, the tank should be fine. 9.5 is safe for dKH. I think that your estimate of the water volume for the tank was a bit high. Maybe there's more live rock than you thought.

 

[WWIII]

Thanks for the advice! Yea I just have fish in there currently. I am trying to get the tank parameters stable within recommended values before I add coral. I retested this evening and alkalinity is at 9 dkh. I'm really happy with that and all my other parameters. If the alkalinity levels out here around 9 dkh I will start to introduce some corals next week and go from there.

Pretty sure you are right that I overestimated my total volume, also I didn't really stir the baking soda solution. So I'm sure the bottom was a little stout, where the top off water is drawn from. Doesn't appear to have had any negative effects on the fish and I'm happy with my level now so it all worked out well! Thanks again for the pointers!