precipitation? , mega dose of 2 part needed

[IPT]

Ok, I am using an un-Godly amount of two part (recipie 1 from two Part Solutions). It's only a 20L with a 15 gal sump (the new stand and overflow silicone is drying on the 50 it's all going into). granted it's cramed with SPS, an 8" Derasa, Galexia, and Favia. I am using 280ml a day to keep things level. That is what it is taking to keep things stable at 400Ca, 9.3-9.6 dkh, and mg of 1240 (a tad low - I'm working on it) I started at 200 but levels were dropping. It's been stable here for 2 days now at, yes, 280ml via a LM3!

There is visible growth on nearly all the species regularly. I cleaned the pumps last week and then is only a slight layer of build up them so far. I also dose with LM3. I did use to get a lot of precip when dosing manually. I was still using well over 100ml of C balance a day but when I administered it I saw it go white. With the smaller doseing I don't see that.

Several ideas have been presented. Precipitation being the most suspected. My question is if it were causeing a precipiation wouldn't there be a big snow storm with a rapid dropping of measurable Ca or Alk? Shouldn't the small doses from the LM 3 minimize if not prevent precipitation. Alk dosed at the return to the sump (from a Mag3) and Ca into the tank righ over a Korollia 2.

Assuming I mixed it wrong (but I added 2 cups solid per gal RO water) how can I measure the strength of the solution? ie, how many ml of part A added to Xml of tank would water to raise the Ca by sat 20ppm?

I understand that tanks with many more gallons and huge SPS do not use this amount of solution. It must be going somewhere. I need some help trouble shooting this from someone with a lot more experience and knowledge than I have

[JetCat USA]

Originally posted by IPT
........an 8" Derasa.

with that size clam your dose seams about ballpark to me.

[IPT]

JetCat - thanks for your input. Really? Yikes - he's gotta go (kidding)! Actually he's gonna be moved into a 75 I'm setting up at the office. Probably won't be able to just use Kalk huh?

Two questions -
1 - Is there any way to increase the concentraion of the two part so I can still use 1 gal containers but not have to re-fill so often (or is it saturated already)?

2 - is there a way test the concentration of the two part or it's effectiveness at raising levels within a tank (to see it is all becoming available and not being bound up or precipitated)?

[bertoni]

1. The solutions are as concentrated as is practical for hobbyist equipment.

2. You could test just before and after a dosing, to see whether the calcium is precipitating quickly, but, as you've stated, you'd be seeing a snowstorm. Weighing your clam might be more appropriate, if a bit too accident-prone to be practical.

[JetCat USA]

big clams play hell even on large systems running a CaCO3/CO2 & Kalk reactor, it's just one of those things you've got to deal with if you want large clams.

how are you topping off the tank currently??

[IPT]

Tunze Osmolater. I was using 2tsp Kalk per gallon but I am probably using about 1 and 3/4 cups per gallon now. My PH was slowly creeping above 8.4. It's more around 8.3 now give or take a little.

I was wondering if the Kalk addition was causing precipitation? Seems like most build up is in the sump where it is dosed. I wonder if that were the case if my Two part needs would go up or down if I used pure RO water?

[IPT]

Opps, not "cups", 1 3/4 tsp's per gallon. I know someone once told me too proof read.....

[bertoni]

Limewater is high-pH, and thus when dosed into a sump, it might cause precipitation if the flow rate is low enough. The same can happen with a 2-part. I'd guess the 2-part requirement would go up some if the limewater were discontinued, although a downward pH shift might happen, and that could reduce growth and drop the demand for calcium and alkalinity.

[IPT]

My sump feeds that tank Via a Mag 3 . It drains thru a CPR (Can't wait chuck that thing and get the drilled tank running!). The drain a 3/4" and both the Kalk and 2 part addition hoses are situated right above the exit so it is a fairly high flow area.

Less growth? Looks like I'll just be mixing up 5 gal jugs

Thanks for the insight. I guess I way underestimated the consumption of resources from a clam that big. There will be less light in the 75 so hopefully he'll slow down.

[kysard1]

if your magnesium is low you won't be able to maintain Alk and Ca.

[JetCat USA]

what I'd do is add CaCl to the top off water rather then Kalk and keep an eye on the Alk levels and adjust the Ca levels of the top off water as necessary.

[IPT]

What exactly is the difference, if any, between Ca build up and precipitation? I understand precipitation as being the falling out of solution of an element on a large scale. Even though I don't see it readily, on some scale it's happening in my sump. I just had to rescue a fish from my sump and there is a layer of white crusty material on the bottom of the sump. Can precipitaion happen on a small scale or once you hit the threshold is it all or none?

What about Ca build up (?) on the walls of the sump and other non heat generating items like the eggcrate stand for my pump? It doesn't even make sense because I dose the Ca portion into the tank. What am I finding in the sump?

Aside from high flow and dosing small quantities at a time is there any way to prevent or minimize this? Sorry to be a PITA.

[bertoni]

Precipitation of calcium carbonate can occur for a lot of reasons. The "buildup" you're discussing most likely is just precipitation. Dosing the alkalinity (carbonate) into the sump is more likely to cause precipitation than the calcium part, because the alkalinity part is high-pH, in this case. Calcium carbonate is less soluble at high pH levels.

Since the Mg level is fine, all I can suggest is spreading the dose out more, perhaps with a dosing pump or a drip. The low-pH version might cause fewer problems, too, if the tank's pH is fine that way.

[IPT]

That's an idea. MAybe recipe 2? I already use a LM 3 for dosing so I can't imagine it could be spread out much more. It also releases it right at the exit of the tank drain so the flow is fairly substantial. I think my Kalk will keep the PH up. I will consider the low PH version, or just clean my sump and equipment more . Thanks again for the advise and input.

[IPT]

Okay, a curious addition to this fiasco. I just retested. I have been dosing at 280ml a day for the past 6 days. I also added suplemental Turbo Ca which I recently decreased (I added 3/4 a tsp this morning, down from 2). My Alk dropped from 9.3 to 9.0. However, my Ca dropped from 390 to 360 (cross checked on Salifert and API kits). I thought Ca was more stable than Alk? My mg is okay, so why am I needing to shift the ratios of the two part to stay in balance?

[paulhines]

My guess is the Magnesium is low. I was having the same problem, and increasing the Magnesium has helped. Use the powder/granular magnesium chloride or sulfate, as you'll probably need a lot. Buy a Salefert test kit.

[IPT]

last mg check was 1240. within acceptable range I think. I am upping it anyway. Thanks.