Curing cement/oyster shell rocks

Daniel@R2R · Apr 13, 2018

Also, maybe @Randy Holmes-Farley can offer some insight into getting the chemistry in balance.

headdr · Apr 13, 2018

headdr · Apr 13, 2018

headdr · Apr 13, 2018

Thanks Bob I may take u up on that. Been trying to address this one thing at a time focusing on alk. It sounds like this my need a multi prong approach. Going to follow the recipe from Mr Farley. Trying to round up some ingredients. Currently only a few blue legs in there so I will play with additives. Still trying to decide on a skimmer so got time.

headdr · Apr 13, 2018

chipmunkofdoom2 said:
Something is very wrong with the chemistry in this tank. There's no way your magnesium should be 700 ppm. Alkalinity is also way, way off at 4 dKh. What is your salinity? How are you measuring salinity? What test kits are you using for alkalinity and magnesium? What is your calcium?

Personally, I would correct salinity if it's off (I suspect it is), then I would do a large water change. I know it's a big system, but Instant Ocean is only $50 for a 200 gallon box. You'd rather spend your money on corals, I understand, but this hobby is more about keeping water than it is about keeping fish or corals. You're not going to get anywhere by cutting corners with water quality.

Agreed this is a good learning experience to learn what to do before there are any sensitive fish or critters in there. My nano is pretty much on auto pilot given it size I don't really have to do much. Just softies.

headdr · Apr 13, 2018

Salinity is good, using a refratometer and an apex probe. Curing these rocks really spiked my calcium. I have added a $15 container of aqua forest magnesium and it barely moved my level. I trust what Bob is saying gonna need pounds magnitude. Gonna buy that bulk from Brenntag's chemical wholesalers.

headdr · Apr 13, 2018

Flippers4pups said:
Agreed the about magnesium dosing.

Here's a good read on alkalinity supplement dosing:

http://reefkeeping.com/issues/2006-02/rhf/index.php

I use Randy's part 2 for alkalinity to keep my alkalinity where I want it. I make it into solution using his recipe.
Then I dose it using this calculator:

http://reef.diesyst.com/chemcalc/chemcalc.html

Thanks for the links to the recipes.

beaslbob · Apr 13, 2018

Dustin Head said:
Salinity is good, using a refratometer and an apex probe. Curing these rocks really spiked my calcium. I have added a $15 container of aqua forest magnesium and it barely moved my level. I trust what Bob is saying gonna need pounds magnitude. Gonna buy that bulk from Brenntag's chemical wholesalers.

I just checked with the on line calculator. with a 300g tank and raising 700ppm magnesium to 1350ppm requires 256.8 oz of Epsom salts, or 217oz of magnesium chloride. That should help explain why a bottle of stuff didn't make much difference. The diy 2 part solutions which are 3 cups Epsom salts 5 cups magnesium chloride in a gallon of water require 15 liters of solution. At 16 oz per pound looks like somewhere around 12-15 pounds need to be added. you could also do the 3 to 5 ratio of the dry powder But I'm pretty tired of math by now. LOL

(FYI myh 55g took 4-5 pounds so my "gut feel" is these values and your experience are similar to mine. )

FWIW I was using instant Ocean with my 700ppm magnesium. After two doses of pounds it was 1400ppm and after that the diy two part maintained it at over 1300. After using up a gallon of the calcium/alk supplement magnesium was lower. And responded as advertised to the correct value after dosing the 300ml of the magnesium solution.

my .02

headdr · Apr 13, 2018

I called Brenntag chemical wholesalers. Can get magnesium chloride for $18/55lb bag. BRS has a $23/7lb bag. That's .32 cents per lb versus $3.29/lb. I need about 20 lbs to start with not to consider long term. So $6.50 versus $66. Long term that is significant.

beaslbob · Apr 16, 2018

How are things going?

headdr · Apr 17, 2018

Got magnesium up to 1150. Alk is still 5.6 dk, dosing baking soda. Calculator said about 6 table spoons to get it up to 8 or 9. Calcium is still off the chart on my API test. Gonna run carbon for a couple of weeks and try adding a few snails. Blue leg crabs are doing fine.

beaslbob · Apr 17, 2018

sounds like progress.

Tomoko Schum · Apr 22, 2018

How is it going now?

Here is an article by Dr. Randy Holmes Farley that may help you (Check out the correction for zone 4 (high calcium with low alk situation):

https://www.advancedaquarist.com/2002/11/chemistry

I try to keep my magnesium up to the natural sea level in order to keep calcium high enough since calcium will not go up if magnesium is too low. You've got an opposite situation.

Be careful using a lot of magnesium at once. Magflake type magnesium additive such as the one from Brenntag contains ammonia (a byproduct of processing).

headdr · Apr 22, 2018

Getting better gradually. I don't want to hurt Bob's bad reputation, but he really helped me out. Got some good magnesium from him. Been dosing baking soda also so got alk up to 7 dKh and mag is has leveled off at 1050. Was a little higher when I first dosed it heavily last weekend. Gonna try to get up to 1350 by the end of the week. Just set up a new reef octopus skimmer. Hope to be fish ready before June.

cracker · Apr 22, 2018

Nice work on the rock You made. I'd leave the sock & do a big fat water change. That's a big tank You have. Got a couple of 40 gl brute cans for mixing? But Like You said, You have time to work this out.

Brew12 · Apr 23, 2018

Dustin Head said:
Getting better gradually. I don't want to hurt Bob's bad reputation, but he really helped me out. Got some good magnesium from him. Been dosing baking soda also so got alk up to 7 dKh and mag is has leveled off at 1050. Was a little higher when I first dosed it heavily last weekend. Gonna try to get up to 1350 by the end of the week. Just set up a new reef octopus skimmer. Hope to be fish ready before June.

I wish I had seen this thread earlier. I need to pay more attention.

With your alk up this much, how far has your calcium dropped?

And in case you haven't noticed, you can expect to fight diatoms for quite awhile in this tank. They shouldn't hurt anything, and the more of them you grow the faster they will phase out. Just a little less than pleasant to look at.