Need help with ph, Ca, KH

[wyvern]

Hi,
I have a problem with the ph, Ca, and Kh levels and I don't know how to fix them. I use ro/di water, Oceanic sea salt (don't like it, gonna try something else). I let the water mix for 24 to 48 hours. I don't use any buffers or anything. I do a 15 gallon water change when I get the chance (not often enough). If the purple tang breaks with ich, I do a water change. At this time the tang looks great. Unfortunatly, the xenia is fading fast. Yeaterday, it looked great. Tonight, it's just about dead. I tested the water this morning and did a water change. Started more water mixing if I need to change again. What do I need to add to fix the problem.
~70lbs LR, Purple Tang, 3 stripe damsel, 3 spot damsel, blacksailfin blenny, 2 emerald crabs, and a few snails. Oh, and the very sorry Xenia (It's been in the tank for about 8 months and was the last thing added). I'm having a temp swing because of the heating in the house.
100 gallon tank (16 months old)
Temp 80 to 83
sp 1.024
ph 7.8
Ammonia 0
Nitrite 0
Nitrate 0
KH 90ppm
Ca 600ppm
Thanks for the help.

 

[hatessushi]

I have a 90 gallon with Xenia and it grows like crazy and looks great. My water parameters are similar except my CA is around 420. Your CA is really high which is typical of Oceanic salt which I used to use and quit it because not only was the CA low the alk was low and the pH was low. I switched to Tropic Marin pro since I heard it was the best but the most expensive. Now I am finishing that bucket and will use something else since it gives similar reading as the Oceanic.
My pH is a 7.8 also which is on the low end but should not cause the Xenia to start dieing off. Seawater pH is from 7.8 to 8.3. My SG is 1.025, you might think of raising yours from 1.024 to 1.025 or 1.036 since corals need the SG on the higher end.

 

[wyvern]

I'll up the SG over the next few water changes. I'm thinking of using some Kent Marine Superbuffer-dKH. Do you think that will bring the Kh and ph up? What do I do about the Ca level?

 

[michaeltx]

you might think of raising yours from 1.024 to 1.025 or 1.036 since corals need the SG on the higher end
make that 1.036 to a 1.026
1.036 is a high SG
I new batch of change water may help what additives have you added to the tank and when was the last water change?
Mike

 

[hatessushi]

Originally Posted by MichaelTX
make that 1.036 to a 1.026
1.036 is a high SG
I new batch of change water may help what additives have you added to the tank and when was the last water change?
Mike
Oh, dang my mistake. That was a typo. I meant 1.026. Sorry.
If you add the super buffer it will raise your pH and your Kh. The probelm with that solution is that your pH will just go back to what it was in a day or 2 but your Kh will probably stay so if you add it again your pH will go up for a day or 2 but your Kh will build up until your Kh is way to high but your pH will be back to the low number again.
That's the probelm with uding buffers.
The salt you are using is making your CA that high. I would just finish up what was left and get some other salt. Some people really swear by Oceanic and can deal with the high CA especially in a reef aquarium.

 

[michaeltx]

I decided to try a different salt and used red sea this time. all my readings so far have been great. PH holding at 8.0 *wish it was 8.3* alk 3.25 KH 11 and calcium at 420 i have been pleaseantly surprised.
I think you cought one of my mistakes the other day

Mike

 

[hatessushi]

Originally Posted by MichaelTX
I decided to try a different salt and used red sea this time. all my readings so far have been great. PH holding at 8.0 *wish it was 8.3* alk 3.25 KH 11 and calcium at 420 i have been pleaseantly surprised.
I think you cought one of my mistakes the other day

Mike
I was thinking of trying the Red Sea salt since I was disappointed in Oceanic and Tropic Marin Pro Reef. Thanks for the tip MichaelTX

 

[wyvern]

Thanks for the help. The last water change was yesterday morning. I think I'll try Red sea salt. I haven't added anything to the tank yet. If I add the superbuffer, will some of the Ca precipitate out? Should I add something to the top off water to up the ph? The top off water is about a ph of 7.2.

 

[bang guy]

Magnesium would be a very good parameter to know if you're going to attempt to precipitate Calcium.
If Mg is already low and you precipitate Calcium using a buffer then there is a possibility of lowering the Mg below the level when Calcium can remain in a supersaturated state.
This means you could have a catastrophic precipitation event.
I believe you are correct in your assumption that your low Alkalinity is stressing your Xenia.

 

[wyvern]

Thanks Bang Guy. Any ideas on how to fix the problem. I don't think the Xenia gonna last much longer.

 

[bang guy]

If it were me I would probably do a large water change with a different salt.

 

[wyvern]

Thanks. Unfortunatly, The LFS around here only seem to sell Oceanic and instant ocean. I'll order some salt online. Bad news for the Xenia. What do you think about adding something to the top off water to up the ph?

 

[bang guy]

Originally Posted by wyvern
Thanks. Unfortunatly, The LFS around here only seem to sell Oceanic and instant ocean. I'll order some salt online. Bad news for the Xenia. What do you think about adding something to the top off water to up the ph?
Like I said above, it's risky to add an alkalinity additive with Calcium that high. If you have no choice go ahead and do it but not too much too fast.
What's wrong with Instant Ocean salt?

 

[wyvern]

I couldn't get the instant ocean to dissolve all the way. I used two different bags. But, I'll get another bag today and do a 20 gallon change in 24 to 48 hrs. Thanks again for all the help.

 

[wyvern]

ok, It's been a couple of days. I've done two 20 gallon water changes using Red Sea Salt.
After 1st change
ph: 7.8
sp: 1.025
kH: 100ppm
Ca: 540ppm
After 2nd change
ph: 7.8 ~7.9
sp: 1.025
kH: 100ppm
Ca: 520ppm
The Ca level is slowly going down, but the kH is not moving much. Do I keep changing the water or do I add a buffer or something? Thanks for the help

 

[gatorwpb]

What kind of turnover do you have in your tank?
To get that pH up a little, maybe you need more agitation in the tank for more air contact.
I noticed my pH dropped for a day when I removed my maxi-jet powerheads and ordered new tunze nanos.

 

[wyvern]

There are 3 maxi-jet 1200 in the tank and the return pump is 1200gph. I have one of the maxi-jets pointed at the surface. I think I just lost a Emerald crab. What's going on with this tank?