possible causes for low alkalinity

[enosmeanus]

what can cause low alk? Mag is @ 1230, ph 8.3/8.4, cal is around 335 ppm. alk with daily supplements of seachem reef builder, is hard to get over 8 dKH, i guess i could up my dosage but i don't want to cause any damage. adding 1/2 tsp to approx. 60 gallon water volume, (display tank/sump) twice daily. test kits are salifert, (new). what can i do? think it's the cause for the deterioration of a hammer coral i have, other corals, (frogspawn, toadstool, xenia, ricordia, and colony polyps) seem to be doing ok.

 

[enosmeanus]

trates are around 20 or 25 ppm, phosphates are at .01, maybe .02 ppm.

 

[belothsurf]

Yours is not too low. 7 -10dKH is where you want to be. To keep it higher, you may need to do more frequent water changes.:happyfish

 

[gregvabch]

i thought it was between 8 and 12 dKH....

 

[belothsurf]

I've actually had mine as high as 15dKH, and everything seemed ok....but on the 7-10, I'm quoting from a book. But that's just one source. The lower it get's, ph can fluctuate more, so higher is better.

 

[benj2112]

Isn't 335 ppm Ca a little low actually (400 to 450 is where it should be)?
I would think a dKH of 8 is fine for where your Ca is, but if you raise Ca you might want it higher (ie. Ca of 420 then dKH of 8.4, Ca of 430 then dKH of 9.8, Ca of 440 then dKH of 11.2, and lastly Ca of 450 then dKH of 12.6).

 

[belothsurf]

Calcium isn't really related to alkalinity or carbonate hardness. Alkalinity is a measure of your water's buffering capacity, which in turn resists fluctuations in your ph, which is a measure of how acid or base your water is, which is what most fishies and inverts are very sensitive to. If your alk is low, you may have an acceptable ph, but anything that may cause a big shift in ph would cause it to fluctuate too much and too quick, which is a bad thing.

 

[col]

Alk - pH and Calcium are all related (and mag).
What is in your tank? If it is fish only then I wouldn't worry too much.
If you have corals I would raise the calcium to 400 - 450 then take readings again.

 

[belothsurf]

Originally posted by Kip4130
careful with some of those relationship statements belothsurf
while i know what you mean......
Ca is directly related to dkh (alk) and pH ... they have a seasaw effect on each other if adjusted independently
for the OP.. i suggest buying a two-part Ca and dkh (CO3) additive and bringing Ca and dkh up together (for their relationship reasons )
I like to shoot for 440-11 .. but around 420-9 is fine... thats NSW levels.
......uh....I knew that......:nervous: ..uh...I just forgot...