high kh low ph????

[toddmcgill]

ok i am setting up my new tank and am having some issues with ph,if i run my calcium reactor i quicly build up to high of an alk,so i quit running the ca reactor, assuming there is no need with no corals useing it up, however my ph is remaining low, around 8.1, i dont get it. i thought high kh meant high or stable ph? my kh has now dropped from 15 to 12.5 since turning the reactor off but ph is still low. right now the only live stock so to speak is approx 250 lbs of tonga branch and kalini mixed rock mostly cured . it's been curing for around 2 weeks,and 35 lbs fiji colony zooanthid rock recently added,which came in nice but has since closed up and for the most part looks po'd, which i assume is due to it being shipped damp not submerged and now going through a curing process, as i do have ammonia levels again since introducing the zooanthid rock. aprox .75 via a salifert test, nitrates are around .25, and the lfs didnt have a nitrite test so no info there,

i guess i am wondering if the acidity of the curing rock is the cause of my lower than normal ph, and is so why hasnt the buffering ability of the 12.5 kh kept that from happening, and how can i raise it without raising the dkh again,or should i even worry about it?is 8.1 ok for now,
i really dont want a of the zooanthids to die,already 95 percent of the original live rock's corraline died of from its curing period, and i thought 250lbs of cured rock would be enough to cure 35 lbs of colony rock but apparently not since i am showing ammonia readings.

ohh also here are my tank stats so far.

280 gal display
150 gal sump
40 gallon dsb sump.
asm g6 skimmer
barracuda closed loop w/oceans motions 8 way.
snapper return pump for sump.
dual chamber octopus calcium reactor.with diy ph probe holder in first chamber
miluwakee ph monitor in sump
2 400w reeflux 10k on main display till 1000's come in then 400's will be over sump refugium.
1 hp chiller.should arrive monday.

[toddmcgill]

well i may have answered my own question about if 8.1 is k for ph,saw another thread where everyone ws saying this is ok,i always heard 8.2 to 8.4 was optimum.but perhaps not, looks like my main issue is the ammonia and recycling of the system.

[NeilPearson]

I wouldn't worry about pH until the tank is fully cycled. And then if it is low and the alkalinity is fine, it is usually a sign of carbon dioxide in the water.

Running a ca reactor will lower the pH while raising alkalinity and calcium because it is injecting carbon dioxide into the water. I would keep the alkalinity at around 8-9 with the calcium reactor and if you have a good skimmer and decent water flow, your pH will be fine... 8.1 is fine, especially if you are running a ca reactor since it does lower the pH.

[Randy Holmes-Farley]

The ph range from 8.0 to 8.4 is fine, and some folks run down to as low as pH 7.8 OK (although not optimal, IMO).

This article has more:

Reef Aquarium Water Parameters
http://www.reefkeeping.com/issues/2004-05/rhf/index.htm

Also, buffers are not a good way to boost pH. All you end up doing it boosting alkalinity. This article has more:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm

[toddmcgill]

thanks guys, i apreaciate the info and reading links.

[Randy Holmes-Farley]

:thumbsup:

Good luck. :)

[toddmcgill]

if you dont mind i do have a few other questions randy,
this is the first time i have used 100% fresh live rock to start a tank in the past i always had access to plenty of precured rock, so things generally were very quick to get going with minimal startup issues.
so i am dealing with some things i havent had experience with in the past,like sky high nitrates,my ammonia finally zeroed out 2 days ago, so last night i did a 300 gallon water change ,thinking that would get nitrates down to reasonable levels and i could then begin to plan coral and fish additions,for the future,well after changing 300 of the 400 gallons a 75% change i still have nitrates over 50 ppm.thats with a 6 to 8 inch deep remote sand bed in a 40 gallon rubbermade tub,and they seem to be still climbing,i have to assume that even though my ammonia has zeroed , that i still had considerable nitrites which are being converted to nitrates, erhaps i jumped the gun on the water change,but i am really trying to keep any further die off from occuring on my zooanthid rock,i realise adding zooanthid during the curing phase wasnt the brightest thing in the world to hav done but it was basically offered t me for live rock prices so i took it.
anyhow,what i am wondering is, if i am correct and the tank at this oint has basically reached a bacterial equillibium which will keep ammonia and nitrites in check, but still has a fair amount of die off and decay going on from the rock, then my nitrates will continue to rise as the waste is converted,apparently my sand bed cant handle this kind of load, or either hasnt had the time to build the bacteria load that it takes to do so,
so my questin is do i continue to do water changes to try and remove the nitrates manually?or would i be better off just to let nature run it's course an wait a week or two longer untill i am sure the rock has fully finished with any further decomposition.and then do a water change,even then i am concerned that a water change wont get sufficent amounts of nitrates out f the system,heck i did 75% last night and still had 50 ppm or worse.
so far in 3 weeks i have been through 1200 gallons of salt mix, and i would just as soon not continue to throw money away if it has no payoff, however if it will benefit the system and possibly keep me from losing the zooanthid colonies it would be worth it,

any and all advice would be greatly apreaciated,
current stats as tested are
ammonia 0
nitrites ???? no test kits availabe yet
nitrates 50-70 ppm
ph 8.2
temp 80.1
calcium 370
alk 11.5
phosphates lost the colr chip but barely able to detect blue tint
silicate 0


tahnks again

[Randy Holmes-Farley]

The nitrate reading may be a false positive, if there is elevated nitrite. A small amount of nitrite reads as a lot of nitrate with some kits.


but still has a fair amount of die off and decay going on from the rock, then my nitrates will continue to rise as the waste is converted,apparently my sand bed cant handle this kind of load, or either hasnt had the time to build the bacteria load that it takes to do so,

I do not know if it will ever be enough, but it also takes considerable time for such sand beds to develop adequate capacity.

I personally would not worry about nitrate for a while yet.

[toddmcgill]

thanks again randy.
at what point would you consider it safe to add a fish or coral to the system,when nitrites and ammonia are gone or do i need to wait till nitrates are gone also?

[Randy Holmes-Farley]

It is always good to ramp up slowly, and start with more hardy organisms, but having ammonia gone is the big one. Nitrite is unimportant, IMO. Nitrate may never go away, depending on the setup.

[toddmcgill]

thanks again randy, this is going to be a sps mainly medium fish lod system, and i definitely plan to keep the nutrient levels as low as possible thats why,i incorporated the 40 gallon tub with 200 lbs of live sand as a denitration station,hopefully it works, at the moment i just want to add a tang or 2 to try and keep ahead of algae before it gets a foothold while nutrients are still high from the cycle.
thanks again for all your advice.

[Randy Holmes-Farley]

How were you going to export phosphate?

[toddmcgill]

well i am trying to limit input of phoshates,by useing rodi,and such, but plan to run a phos ban reactor also,right now i am useing a sock full of the iron based removal media in my sump, since the lfs didnt have the reactors in stock,
my only concern is what else the ferrous oxide or whatever it's called is going to remove,i know it is very aggressive ionically twards phsphate but surely it must remove other compounds also.

i also intent to run some sort of fluidised bed or cannister for carbon, perhaps you could advise on weather a fludised bed would be ok for carbon or would the tumbling create powdered carbon which would escape the reactor.

i have also been contemplating the zeovit method , but dont know enough about it yet to make an informed decision. any thoughts on this???

[toddmcgill]

ohh yes as for nutrient exort i will also have 400w mh over my 150 galln sump with live rock and algae refugium incorporated and harvesrt chaeto to remove some nutrients, hefully this will make used of the iron oxide minimal.

[Randy Holmes-Farley]

i have also been contemplating the zeovit method , but dont know enough about it yet to make an informed decision. any thoughts on this???

I'm not personally a fan of zeovit or other bacterial growth methods to reduce nutrients, but many folks seem to like it. The macroalgae and skimming are my favorites. :)