Reverse Osmosis

[blue_ram]

Given my recent change from soft slightly acidic water perfect for my tansk to a slighlty harder more alkaline water whcih appears to be causing stress for my fish or plants, I think I have no choice but to purchase a RO unit.

Are there any other options. My Brita filter drops the PH to < 6, but that woudl seem to get pretty pricey replacing 25 gallons per week.

I found this: CORALIFE Pure-Flo II™ Premium TFC Reverse Osmosis Water Purification System and Accessories - Aquarium Maintenance - Fish - PetSmart

Oops that is for the membrane only, the whole shebang is here:

CORALIFE Pure-Flo II&#153 Premium TFC Reverse Osmosis Water Purification System and Accessories - Water Conditioners - Fish - PetSmart



Seems pretty inexpensive, but 24 GPD is more than I need.

[brian1973]

I dont know much about RO but I recently saw someone say that RO lacked many trace elements that you still need in your tank, not sure how to get those if you go the full RO route. I would be interested myself since where I live now doesnt have the best tap water. good luck.

[Lotus]

If you only need a few gallons of RO water a week, it would probably be easier to either buy it at your LFS or get it from the machine at the supermarket (Culligen or Glacier, most often).

Usually, it's easier to mix RO and tapwater to get the buffering/pH you need. RO has no buffer, so is subject to pH swings if you use pure RO water. You would need to use the same proportion of RO:tapwater weekly to give a consistent water for the fish. The alternative is to use RO and add one of the additives (Seachem makes one) that put buffer back into your water.

[blue_ram]

Originally Posted by Lotus

If you only need a few gallons of RO water a week, it would probably be easier to either buy it at your LFS or get it from the machine at the supermarket (Culligen or Glacier, most often).

Usually, it's easier to mix RO and tapwater to get the buffering/pH you need. RO has no buffer, so is subject to pH swings if you use pure RO water. You would need to use the same proportion of RO:tapwater weekly to give a consistent water for the fish. The alternative is to use RO and add one of the additives (Seachem makes one) that put buffer back into your water.

My 40g is testing at 7.0 now and I usually only do small 2.5 gallon water changes every 2 days or so. The last test in the tank was done after a 10% water change because I dropped the water a few inches tryign to hatch the cory fry in the breeder net.

Tap water still tests at 7.8. I have read that plants consume calcium whcih drops ph. The 20 only had a small ludwigia stem and an anubias and a small bit of water sprite. The 40 is moderately planted with lots of amazon swords, dwarf chain sword, lludwigia, red temple and Limnophila hippuroides

If I keep the tanks well planted and only do small water changes more often, will the ph still be a factor?

[Lotus]

To be honest, if you're doing regular water changes, the plants' use of calcium shouldn't be a factor in pH changes. They certainly don't use massive amounts weekly.

[blue_ram]

2.5 every 2nd to 3rd day equals about 12-15% per week. In hind sight I am lucky I haven't been doing more because the fish in the tanks where I did do more have died.

25% water changes seem to be a bad idea with my tap water having .50 ppm ammonia.

It is interesting that the 10g which had a 100% water change less than 2 weeks ago and a 10% since also has a much lower ph and that tank has a bunch of water sprite, ludwigia and java fern.

What else could be in the water which raises PH. I am in South Florida so I presume high calcium.

[Lotus]

This article is great for explaining GH/KH/pH. Unfortunately, this is the cached version, as the original seems to have disappeared: Aquarium Chemistry, pH, gH, and kH relationship

[blue_ram]

Cool, thanks.

[blue_ram]

Originally Posted by Lotus

This article is great for explaining GH/KH/pH. Unfortunately, this is the cached version, as the original seems to have disappeared: Aquarium Chemistry, pH, gH, and kH relationship

That was a good quick read. I alos noticed the part about ph causing excessive slime coat and remember someone here had a problem with that and sick fish.

So from my tests, I have soft water with a GH of 120ppm or 6.7 dH.

The KH is the same as the GH in the tank at 120ppm or 6.7 dH

From what I read, it appears that although the ph is somewhat high, the buffering ability or ability to absorb acid is low and that with low KH, the ph can drop fairly quickly.

So with 2 AQ 50's handeling the bioload of a mildly overstocked and over fed 40g tank, is it possible that enough nitrates are being produced and absorbed by the plants to reduce the PH or the stop the PH from rising with my small but frequent water changes?

If this is correct, then as long as I keep up with what I am currently doing, the PH of the tap water is irrelevant as the small water changes are not enough to raise the ph, but it does add a steady stream of buffers to stop a PH crash.

[Pure]

Most fish should be fine in your water. If they are dying off then you are changing the peramiters to rapidly. I've kept/keep discus and blue rams in the same florida water. The only time you need RO is when you are breeding your GBR as the fry don't make it in higher PHs.

For an RO unit go to ebay. The gallons per day on the coral life is crap. For the same if not less $ you can get any number of 100 GPD, and pretty much all of them work just as good.