Alkalinity drop big time

[KahluaZzZ]

Ok guys now since i started my sump like 3 months ago, my alkalinity dropped from 11 dkh to 6.74. I have serious ph drops from night to day ( 7.8 to 8.3 ). It usually was from 8.1 to 8.3 ( Seatest ph test ).
My tap/ro-di water here is very hard and when my tank was new, i had "too much" alk. Anyways, should i ditch the caulerpa completely, because it seems that this plant is depleting alk very quickly.
I don't have corals or fish problems now ( BTW the zoos recovered from the Al shock ) but i always have to monitor alk and ph, and i don't like to use the marine buffer often.

other params :
calc : 420 but depleting fast.
nitrite : 0
ammonia : 0
nitrates : >2 ppm
po4 : now undetectable
temp : 79 steady

I don't have big probs, but i wonder if i should remove a good no3/po4 remover to raise alk. Also, my sump is 30 % filled with chaetomorpha..it grows, but much slower than the caulerpa. Does this one affect alk as caulerpa does ?

 

[wayne]

See notes

Ok guys now since i started my sump like 3 months ago, my alkalinity dropped from 11 dkh to 6.74.<<Normal, w/ inadequate water changes>> I have serious ph drops from night to day ( 7.8 to 8.3 ). It usually was from 8.1 to 8.3 ( Seatest ph test ).<<Not good>>
My tap/ro-di water here is very hard <<Your ro should not be hard - it's RO dummy>> and when my tank was new, i had "too much" alk.<<No>> Anyways, should i ditch the caulerpa completely, because it seems that this plant is depleting alk very quickly.<<Probably not the case - accumulating organics add an acid load>>
I don't have corals or fish problems now ( BTW the zoos recovered from the Al shock ) but i always have to monitor alk and ph, and i don't like to use the marine buffer often.<<Why not? Use it, or do more water changes>>

other params :
calc : 420 but depleting fast.
nitrite : 0
ammonia : 0
nitrates : >2 ppm
po4 : now undetectable
temp : 79 steady

I don't have big probs, but i wonder if i should remove a good no3/po4 remover to raise alk.<<Pardon? Why will a P remover affect alk in a controllable way. Add alk>> Also, my sump is 30 % filled with chaetomorpha..it grows, but much slower than the caulerpa. Does this one affect alk as caulerpa does ?<<No, barely, use both, these are not your problem>>


You need to provide more alk, a buffer is good, so are water changes with a decent salt.

 

[KahluaZzZ]

When i wrote my alk was too high, i meant calcium was barely over 320.
Accumulating organics add an acid load..you just remembered me that i forgot to prune caulerpa.
I do a 10 % water change every week, and a 20 % every 2 months. I did overfed last week but usually feed 1 time every day, half a cube of SFBay mysis shrimps for a medium size yellow tang, 2 chromis, a 2.5" perc and a firefish. Do you think it's too much ?

 

[aresgod]

well I only feed 2 times a week for an angel, 2 clowns, a goby, and a blenny, plus corals and I feed 2 cubes of mysis and some krill.

 

[wayne]

Well I feed at least twice a day so make what you will of that. I personally would say aresgod is underfeeding, but what works works

I'd say your water changes were adequate. However the 'natural trend' for a tank is to losr alk and drop in pH. I would humm and hah about my choice of skimmer if that was my tank as you obviously have accumulated some organic load.
Another q? - are you supplementing calcium, and if so what with? I would be tempted to just use the buffer more frequently, and maybe move if I was using a salt that mixed up low on alk. Have you tested that?

 

[KahluaZzZ]

I do add reef advantage calcium one a week ( when needed ) , but i don't overdose..that would lead to alk depletion.
My new skimmer is working, but still i had a seaclone for 10 months.
I have used a 160g mix Instant Ocean bucket but now it's empty..my next bucket is a Coralife...but i just read on http://web.archive.org/web/20010303...om/fish2/aqfm/1999/mar/features/1/default.asp (Buffer System Components
After Equilibration with Atmospheric CO2 ) that it's the lowest of all...argh

 

[JustinP]

For what it's worth I switched to CoralLife salt this past summer because it was on sale. I previously always used Instant Ocean. I have found that the CoralLife yields a more stable pH in my tank versus the IO (nothing else changed) and I rarely buffer at all now. I don't know why and I'm not a chemist although I did stay at a Holiday Inn Express last night! j/k

 

[wayne]

What's it stable at?

Know that you can add buffer till the cows com home, you won't go above 8.2, 8.3 but you will be very stable there (until you precipitate all your calcium out)

 

[JustinP]

It always tests at 8.2 - 8.3