Alkaline Water Conditions

[B. Pearcy]

I've filled my grow beds about 20% with rocks sold as river gravel from Lowes and Home Depot. I bought some from both places so far and it appears the same.

I just returned from the local aquaculture association store with my water test kit (the one they recommended) and tested the ph in the grow beds. It's light blue color (no green and not dark blue), but definitely no where near 7.0.

Any ideas whether this is a problem I should try to remedy now by choosing different media, or will this problem subside over time? I have read so many recommendations for using river gravel, I really never thought it would be an issue I would have to worry about.

There has been no cycling yet and no fish in the system, but I wanted to check the ph before it becomes an issue I can't easily correct.

What are your thoughts and suggestions?

[TCLynx]

What is your source water?  Most likely here in FL you have the high pH because the well water here comes from limestone aquifers and even if you have city water the pH is still likely to be closer to 8.  Now if you tell me you tested the pH of your tap water, I'm gonna ask if you let it bubble or outgass for a day before testing.  Water right from the well, holding tanks or pipes generally has dissolved CO2 in it which will give you a false low pH reading if you test it right out of the pipes.

 

The 1/2" brown river rock I've used around here doesn't seem to buffer the pH so I wouldn't worry too much about that being your problem.  It is probably just your source water being hard.  I have used a couple doses of pool acid to bring the pH in my 300 gallon system down a little before starting my fishless cycling.  I brought the pH down to 7.6 and then started the fishless cycling and when the cycling got underway the pH dropped below 7 and I had to add lime to buffer it up or use well water to top up to keep the pH from dropping too far.

[B. Pearcy]

I am using city water, but it has been sitting in the beds for a week exposed to direct sunlight for 4 or 5 hours each day. I have a plan for shade over the fish tank, but until I add fish I thought letting it sit for a couple weeks would help with the chlorine. I have no other source for water in the urban area where I live.

[TCLynx]

If the pH is above 8, I would recommend getting some pool pH down and seeing if you can bring the pH down below 8 and then start fishless cycling.  You don't need to bring the pH down too much since once the bacteria get going, you will wind up needing to buffer it up some.

 

If the pH is somewhere between 7.0 and 7.9, I'd just start the fishless cycling and let it naturally take it's course.

[B. Pearcy]

I found an interesting suggestion about removing chloromine from public water systems.  This article recommends Vitamin C for removing chloromine.

[B. Pearcy]

I looked into Clor AM-X online. They want $48 for 5 lbs. Wow! I only need 1 ounce at a time. I'll need to find it somewhere else.

jon and cat billings said:

You probably should check to see if Riverview uses chloramines instead of chlorine. I have to use twice the recommended dose of clor am-x here in palm bay.

[B. Pearcy]

I think I'll try Prime from Seachem for the chloramine removal.

[B. Pearcy]

Jon,

Thanks for the detailed explanation.  I checked about 6 or 7 different chloramine products at the pet store today. All have statements about not being approved for human consumption or for edible fish. I did confirm with the water department that they are using chloramine to disinfect our water. The report on their website says 3.5 ppm for chloramine, but ranging up to 5.5 ppm at times and down to 2.5 ppm at times.

[B. Pearcy]

It took a little searching, but I found 5 lbs of Cloram-X for $35 which seems like a reasonable price for a FDA approved product safe for edible fish. It's the only product I've found in 3 days of Google searches and Pet Store visits.