Question on dKH

[txreefer88]

Hello NR, 

 

I've got a Red Sea Reefer 250 (65g) for about 1.5 years.  I've battled a couple algae problems the whole way. One is a clearish film algae that covers much of my dry pukani rock, about 1mm thick. The other is a dark brown film on my argonite substrate. I can suck it all out, then it will regrow within 1-2 days. Spotty areas all around tank. My LFS told me it may be due to lack of coraline growth, and maybe lack of pods which can help consume this algae. 

 

I got home, tested my alk and it's about 6.4 dKH. LFS suggested Kent's Purple Tech, and I've been dosing 12-15mL over the past few nights, but haven't seen increase in dKH yet.  All my other parameters were in check.  PH 7.9,  Nitrate 4.0,    Phosphate 0.0.  Not sure if I should just keep dosing until it finally increases? Trying to get it up to around 10-11 dKH.

 

All my fish and coral seem happy and showing growth. Exception would be my new RBTA which I've had for a couple weeks, is not extending its long tentacles like it was the first couple days. He's stayed pretty closed up as my maroon clown hosts it. 

 

Any suggestions? 

[Euphylin me]

if your dkh is off off then something else is likely off as well. Anemones need stable dkh. Baking soda will help raise alk. i would shooot for 9 dkh as it seems to be easier to stabilize. i would check calcium and magnesium as well. personally, i would do some 30 percent water changes every other day. Also, see what alk, calc, and magnesium your salt mixes at as you could have gotten a bad batch of salt

[txreefer88]

As of 3 days ago, mg was 1560 and calcium 400. That was 2 days after a 20% water change.

[Euphylin me]

your magnesium is a little high. i would try dosing an alkalinity supplement like baking soda or soda ash. this needs to be done slowly (as in like over the next two weeks and not over night. once you stabilize your parameters. lets say 9dkh 450 calc and around 1350 mag. you should test alk every day for two weeks and see how much is consumed. this way you know how much to dose i would also recommend getting brs 2 part so you can correct the numbers if you make a mistake

[txreefer88]

Ok. I have kalkwasser powder, should I dose that, and stop dosing Purple Tech?

 

[Euphylin me]

i would stop the purple tech....have you just dosed kalkwasser and nothing else? kalkwasser is meant to replace calcium and increase ph, and it can raise alk (slightly). if you are having problems with alk, i would dose just an alkalinity supplement rather that kalkwasser.

[txreefer88]

I haven't dosed the kalk in many months. Just started dosing the Purple Tech. I will research the baking soda method and go from there. Thanks a lot! Awesome name btw.

[Euphylin me]

Just now, txreefer88 said:

I haven't dosed the kalk in many months. Just started dosing the Purple Tech. I will research the baking soda method and go from there. Thanks a lot! Awesome name btw.

sounds like a plan! and thanks!

[txreefer88]

65g system, did a 16g water change on 10/7, that night dKH was 9.5.

10/8 evening:  9.1

10/9 evening:  8.4

10/10 evening: 8.3

10/11 evening:  7.4

 

So tomorrow 10/12 I was going to do an 8g water change. Should I do this or keep measuring my dkh drop rate? I'll take one more reading tonight.

 

Edit: dKh was 7.4 tonight 10/11.

@Euphylin me

[Euphylin me]

i would do the water change and then measure for the next few days and see if you get the same results. if the results are repeatable, youll have a good indication of your dosing schedule. for sure measure tonight to see what the drop is. kind of weird that it dropped .4 then .7 then .1....but you could measure on monday, then measure on sunday. 2 weeks and see if there is the same drop over the course of the 7 days. this way, you are only measuring twice a week. i think this should give you a decent idea of how much to dose

 

[vegasgundog]

I'd test before and maybe an hour after wc. 

[txreefer88]

So this is weird. Alk is dropping at varying rates... Anyone ever seen this before?

10/8 evening:  9.1

10/9 evening:  8.4

10/10 evening: 8.3

10/11 evening:  7.4

[txreefer88]

Today I did a 6.5g water change. Right before the WC, dKH was 8.1.   Then later tonight, dKH read 7.7 (strange it dropped instead of increasing with WC).

So I tested my mixed water still in the mixing station. dKH was 5.8!  The salt mix was a little Instant Ocean reef cyrstal left over, with Red Sea Coral Pro. Next batch I will start fresh with the RS Coral Pro.