15 DkH on fresh water?!

Using reef crystals, have a box of redsea coral pro that will be next on my list, i did a test on new water as usual before it goes in, and im using sailfert kits all around, (alk, cal, mg) are all 1 week old here is where im at

SG - 1.025
mg - 1450
cal - 450
alk - 15DKH????? this cant be right?!

So i proceed to test it 3 times, then decided.. well somethings off so i tested my test kit with the stuff they provide, test kit proved accurate i would suspect tho that the calcium would be higher and my ph would be off as well, but nope all is well? HELP i need to do a water change today but i dont want to add this to my reef if it is accurate.

 

I read your posts on the other thread, and considering that you're getting different readings between different batches, and the fact that everything else seems fine, this might be relevant...

I've used 3 or 4 different brands of salt mixes over the years, and one thing I've found to be consistent with them is that apparently certain compounds separate and settle during shipping. I can never even get the same SG using the same exact amount of salt unless I stir the mix before using. With the variation you're getting, I'd say that might be a possibility.

 

Good call I notice it clumps so I break it all up but don't mix it well before it goes in my water, now with 15dkh I can't put that to replace my water can I? My dkh in the tank is 11 that's to much of a variation right?

 

I wouldn't use it. Alk is one thing you need to try to keep stable, or raise very slowly if it needs to be raised.

 

Could be, but testing error is still possible. There has been a lot of talk about alk tests elsewhere lately. Reading around 2dkh high, doesn't seem to be that uncommon, unfortunately. Also, if your s.g. reading is off by a bit (even a calibrated refractometer can be off by a bit), then it may not actually be off by that much (if that makes sense?) In otherwords, if your s.g. is really 1.027, then you'd expect the alk to be around 13.5, so, you'd only be off by a 1.5 dkh etc... So, you may want to try another kit if your worried.

However, that said, going from 11 to 15 isn't really an issue if your doing a reasonably small change. Remember kalk is 112dkh for example, so, it's all relative to how much your adding.

If your doing a 10% water change, then you have (.9*11) + (.1*15) = 11.4dkh after the change. So, you'd only be raising the alk by 0.4dkh.

If you do a 20% water change, then you have (.8*11) + (.2 * 15) = 11.8dkh. So, your still raising your alk by less than 1 dkh.

As long as your not going over about 1 dkh or so, you should be fine.

 

Makes sense this way, i did test it 3 times, and usually im pretty accurate but things happen, i did a 20% change and it raised it .8 so i cant complain that much, after all its a reason we do a water change lol, to replenish. ill just have to make sure i mix the salt really good, next week when i do my next water change. i usually do a 10% water change but ive been doing 20% b/c im dosing so much its crazy, a calcium reactor is in order asap.