High KH, unstable PH.... HELP!!

[aromaff16]

Im having problems with the total hardness and PH in my tank. It is a 14 gallon biocube approximately 1 month old. I have 8 pounds of live rock, 1 clown fish, a couple zoos, a couple acans, an emerald crab, and 2 small turbo snails. I've been doing partial water changes every couple days with RO water from my local LFS and I cant seem to get the total hardness less than 11. Ph is also unstable. I've been using aquavitro balance to keep the PH around 8.4 but within 24 hours it drops back down to 8.0 or less and I have to dose it again. My understanding is that the higher the total hardness is than the more stable your ph should be... is that correct or am I missing something. Everything else in the water is fine. Any help would be greatly appreciated. thanks.

[metalhead]

Try a two part ALK/Ca supplement like b-ionic and quit using the PH supp, I'm not familiar with aquavitro but I'm guessing that's what it is. Also, start testing and maintaining Mg levels along with Ca and ALK. Basically, if your Ca, Mg, and ALK levels are all in line your PH will take care of itself. One more note on the two part supps - Never dose for Ca and Alk on the same day.

[Ninong]

Hi aromaff16,

Im having problems with the total hardness and PH in my tank.

Relax, because you aren't.

I cant seem to get the total hardness less than 11.

That's fine! Anything between 8-12 is perfectly acceptable.

Ph is also unstable. I've been using aquavitro balance to keep the PH around 8.4 but within 24 hours it drops back down to 8.0 or less and I have to dose it again.

As long as it's between 8.0-8.4 it's fine. It's acceptable if it ranges from 7.9-8.5. It's only out of range once it gets below 7.9 or above 8.5. Again, relax. Your pH, especially in a tiny nano-cube, will vary considerably based on when you take your readings. It will be lowest early in the morning just before or just after the lights come on and highest late in the day just before or just after the lights go off. This is perfectly normal and to be expected. It's a function of the photosynthesis cycle. When the lights are off, respiration takes place. During this period all of the algae in your tank, including the zooxanthellae, are net producers of CO2, whereas during the period when the lights are on photosynthesis consumes CO2 and produces oxygen.

It's completely normal for pH to vary in the aquarium. The volume of water is not substantial enough to prevent it from doing this. In other words, your little box of water is not the ocean.

My understanding is that the higher the total hardness is than the more stable your ph should be... is that correct or am I missing something.

Your alkalinity helps keep pH stable but pH is also affected by other water parameters. It's important to keep calcium, magnesium and alkalinity within acceptable parameters. If you do that, you won't have any problems with pH. The pH will take care of itself. For larger systems, many hobbyists like to set up a refugium and set the lights over their refugium to operate on a photo cycle opposite the lights in the main display aquarium. That way the algae in the refugium are producing oxygen at the same time that the algae in the display aquarium are net consumers of oxygen and net producers of CO2. It helps to mitigate the swings in pH for the entire system.

You will find that keeping water stable in a small tank requires even more attention that it does in a larger tank. One of the few benefits to a really small tank is that you can usually maintain water parameters by frequent water changes alone, provided you do them often enough. Twenty-percent changes every week should do it for most nano tanks. You should still monitor your water parameters weekly just to keep an eye on things. If your little nano tank should become heavily stocked in corals that turn it into a high demand (meaning high calcium consumption) system, then it may become necessary to use additives to maintain calcium, magnesium and alkalinity.

By the way, what sort of lighting do you have? You will have a hard time keeping most corals, other than softies, in any tank without proper lighting. And proper lighting over a 14-gal tank can be difficult to achieve without overheating the water.

Good luck!



P.S. -- I agree that using something like B-Ionic's two-component calcium-alkalinity product is a good way to manage a small tank. You should be very careful to follow the instructions carefully so as not to over dose. And always wait at least a couple of minutes between dosing the separate parts. You may not even need that if your weekly water changes alone are able to keep things in line.

[aromaff16]

Thanks for the abundance of info!! It will be a big help. As far as lighting... It has a 10,000K coralife bulb and a 25W Actinic bulb. Ive bot the Actinic light on 10 hrs/day and the other light on 8 hours/day. I just started dosing my water with magnesium and copper today. Hopefuly this will help things a little. Question in reguards to light.... If I only turn my lights on every couple days for a while to help control algae, will this effect moy corals? I have 2 frags of acans, and a small frag of zoos. Thansk

[Ninong]

As far as lighting... It has a 10,000K coralife bulb and a 25W Actinic bulb.

What wattage is the 10,000K lamp?

Ive bot the Actinic light on 10 hrs/day and the other light on 8 hours/day.

It would be better to have the actinic on for 12 hrs/day and the 10,000K lamp on for 10 hrs/day.

I just started dosing my water with magnesium and copper today.

I think you have a typo there. You said you're dosing copper. You can't really mean that???

You shouldn't dose magnesium unless you have tested for magnesium and know that it is deficient. In fact, you shouldn't dose for anything without knowing what your measurements are first. And, once more, you should never, ever dose copper. Copper in extremely low concentrations is toxic to invertebrates, especially mollusks and polychaetes. When I say low, I'm talking about low ppb (parts per billion).

If I only turn my lights on every couple days for a while to help control algae, will this effect moy corals? I have 2 frags of acans, and a small frag of zoos. Thansk

Yes, it would be harmful to your corals and it would do nothing to correct the underlying causes of your nuisance algae: nutrients (mainly nitrogen and phosphorus).

Don't forget that the corals you have in your tank are dependent on the algae (zooxanthellae) in their tissues for survival. It's the photosynthesis of the zooxanthellae than provides the corals with most of their nutrition. If you turn off the lights to kill the bad algae, you will also be killing the corals.

[aromaff16]

Yes... defenitely a typo. I meant calcium. lol And the 10,000K bulb is 24 watts. The reason I asked about the algae is because I had a frag of zoos that died and it seemed to have a lot of green algae growth on it before it died... thought maybe that had something to do with it dying. Ill take your advice and up the amount of time that my lights are on too. Thanks a ton!!