Ph Change In Brackish Tank

[kanzaris]

Hi All

To start of can someone tell me what the KH and Alkalinity should be in a Brackish Tank?
My Tank is 150 gal & Salinity is 1.010.
Since we started using RO Water everything is confusing.
The PH in my Brackish Tank is about 7.8, when I put the Salt into the RO Water the PH is 8.4., then when I add the Osmo Prep Marine into the RO Water with the Salt the PH goes down to 8.
All I can think of that my massive piece of Wood is lowering the PH in the Tank. So when I do a water change I am putting water with a PH of 8 into a Tank with a PH of 7.8. I know these fish are sensitive to a PH change. Will a difference of .2 affect the Fish?

Thanks

Sabby

 

[SLC Flyfishing]

Nah, you're well withing the acceptable range of pH difference for your fish I'd think. I wouldn't worry about it at all. what type of substrate do you use? Because if you used reef aragonite it could buffer your pH for you but at about 8.3, it really works quite well.

SLC

 

[kanzaris]

Nah, you're well withing the acceptable range of pH difference for your fish I'd think. I wouldn't worry about it at all. what type of substrate do you use? Because if you used reef aragonite it could buffer your pH for you but at about 8.3, it really works quite well.

SLC

Hi SLC

The substrate I use is black sand.
Do you know anything about the KH/Alkalinity? As more testing kits you get as more confusing it gets.

Thanks again

Sabby

 

[AMS]

Hi All

To start of can someone tell me what the KH and Alkalinity should be in a Brackish Tank?
My Tank is 150 gal & Salinity is 1.010.
Since we started using RO Water everything is confusing.
The PH in my Brackish Tank is about 7.8, when I put the Salt into the RO Water the PH is 8.4., then when I add the Osmo Prep Marine into the RO Water with the Salt the PH goes down to 8.
All I can think of that my massive piece of Wood is lowering the PH in the Tank. So when I do a water change I am putting water with a PH of 8 into a Tank with a PH of 7.8. I know these fish are sensitive to a PH change. Will a difference of .2 affect the Fish?

Thanks

Sabby

A .2 difference in pH won't bother your fish at all, most reef tanks have water changes done with more than a .2 difference. How long do you let the RO water plus salt mix before adding the Osmo-Prep? It takes a while of mixing before everything stabilizes. Your pH might start out high during mixing but then a few hours later drop, nothing to worry about.

 

[nmonks]

As others are saying, the changes you have here are well within the tolerances of your fish. With reefkeeping, you need to factor in the sensitivity of invertebrates that absorb minerals from the water to secrete shells, skeletons, etc. Brackish water fishes by definition are able to tolerate significant changes in water chemistry. Varying water chemistry is probably much more 'natural' to them than being stuck in very constant water conditions.

I would suggest adding something like crushed coral or crushed oyster shell to one of the filters. For my big tanks, a wet-dry filter partially filled with something called "Calcium Plus" worked very well, but I'm not sure this product is still sold. But provided the water stays alkaline in terms of pH and "hard" on whatever scale you're using, that's all the brackish water fish care about.

Cheers, Neale

PS. It's often said -- probably accurately -- that fish don't feel pH, so getting hung up on pH changes is ignoring what matters rather more, the total dissolved solids. Marine salt mix should take care of this, esp. coupled with regular water changes to replenish what's used up.

 

[kanzaris]

As others are saying, the changes you have here are well within the tolerances of your fish. With reefkeeping, you need to factor in the sensitivity of invertebrates that absorb minerals from the water to secrete shells, skeletons, etc. Brackish water fishes by definition are able to tolerate significant changes in water chemistry. Varying water chemistry is probably much more 'natural' to them than being stuck in very constant water conditions.

I would suggest adding something like crushed coral or crushed oyster shell to one of the filters. For my big tanks, a wet-dry filter partially filled with something called "Calcium Plus" worked very well, but I'm not sure this product is still sold. But provided the water stays alkaline in terms of pH and "hard" on whatever scale you're using, that's all the brackish water fish care about.

Cheers, Neale

PS. It's often said -- probably accurately -- that fish don't feel pH, so getting hung up on pH changes is ignoring what matters rather more, the total dissolved solids. Marine salt mix should take care of this, esp. coupled with regular water changes to replenish what's used up.

Hi Neale/AMS

Thanks again for the advice.
The thing I don’t understand is the KH/ALK .Call me stupid if you like.
My Alk is 5.4, so is that not to low for my Brackish Tank?
This is what I looked up on the Internet.
You should perform regular tests for alkalinity, because a low alkalinity can allow water pH to fluctuate, and cause undue stress for aquarium inhabitants. Maintain your aquarium's alkalinity in the range of 2-4 dKH in soft water, 8-12 dKH in hard water, and 7-10 dKH in saltwater aquariums. Be sure to use a quality buffer specifically designed for your water type to raise and maintain your aquarium's alkalinity. Fish have different preferences for alkalinity, for example, African mouthbrooding cichlids prefer a dKH of 10-17, while South American dwarf cichlids do best at 1-7 dKH.

Thanks

Sabby

 

[nmonks]

Hi Sabby,

The whole KH and alkalinity thing is outside my field of expertise, I'm afraid. Never needed to worry about it. I don't think you do, either. I'd forget about making comparisons with freshwater aquaria. These will be very misleading, not least because the array of minerals in your tank's brackish water is very different to those in, for example, a Malawi cichlid tank. A marine aquarium is a better comparison, and you want levels somewhat similar to, but not necessarily identical with, those in a marine aquarium, particularly a fish-only marine aquarium. For a fish-only tank, even a level of 8 dKH is acceptable, and 5.4 for a brackish tank would strike me as being perfect: over halfway between a marine tank and a soft water freshwater tank.

http/www.wetwebmedia.com/calcalkmar.htm

At 50% seawater, you should have so much dissolved minerals in the water that your brackish water fish will fine. I'd honestly not worry about it. Provided your fish are healthy and feeding, you can assume they're happy.

Cheers, Neale

 

[SLC Flyfishing]

Yes you're really just fine not to worry about it at all. In reefkeeping we only look at calc/alk levels when we are concerned with corals etc because of their needs for skeleton maintenance and secretion. The fish as I understand it are only concerned with pH (and even then they're flexible to some extent), salinity/specific gravity, and nitrate levels. Other water chemistry measurements are largely irrelevant for an aquarium. There is a bit of a rift that I can sense between the reefkeepers today, that being those that dose their tanks and those who don't (or should I say won't); I fall into the won't category because I find that all the water chemistry parameters stay spot on with frequent water changes (read whenever the nitrates are above 2 or 3 ppm). All my mineral levels stay where they should because they are replenished by the sea salt mix that I use.

I'd be quite comfortable relying on a nitrate test kit and a pH test kit to do all my water testing in a properly cycled brakish aquarium, that is as long as I wasn't overfeeding the fish (which I know you don't do). Mineral levels and the like sort themselves out with frequent water changes and good water husbandry. Our nanoreef mod steelhealr always says something I like quite well, and I think it certainly applies to all fishkeepers; You are a "waterkeeper" more than a fish keeper. Look after the quality of water you are providing your fish and the rest sorts its self out. This is why I advised you not to use Osmo Prep Marine, it's really not necessary. If you want to that's your right and I support you in doing so it won't hurt anything, but it's really just money wasted in my oppinion.

SLC

 

[kanzaris]

Hi Everybody

Thanks for all your replies. This one had me well confused, but thanks to all of you trying to help out I think I have a better understanding of it all. I think

Thanks

Sabby