KH level for F8?

[J-P]

yes there are 2 scales.. I forgot which is which... one is a hard number one I believe you are correct, is the ppm number.

[RTR]

LOL at the cords into trash cans! My tank room is an electricians nightmare. Have you ever seen any of the pictures? If so, you know that. All the outlets are chest height minimum, most on the ceiling or above head high. There are - I think- 6 separate circuits in use there, with two more in reserve, from two separate circuit breaker boxes.. Everything is GFCI at least, and there are more plug strips than you would believe - everything has a drip loop in the cord, and almost all the plug strips have DIY spray covers. The fellow who did our wiring also worked for the county schools, teaching about home wiring. I asked if he wanted to bring in his students to see our fairly sophisticated wiring - he said absolutely not under any circumstances - the students would decide that they did want to be electricians after all.

Yup, you are correct on the scales used here. But not all countries use the same standards. Here we use CaCO3 for both GH and KH. Other places may use CaO for GH. The numeric scales may not match - do not if CaO based.

[mairdan13]

I do use my tap water for the light BW mixing, and my KH is higher than yours (a plus for me), about KH 9 on the average.

HTH

Just as an aside... What sort of GH levels do you usually expect for light BW?

[Pufferpunk]

I wouldn't worry about those levels for your fish.

[mairdan13]

I wouldn't worry about those levels for your fish.

Cool.. thanks

[RTR]

What I want for F-8s is KH >8-9 for light brackish minimum, and I am happier if GH is about the same. I know that the alkalinity (KH) is important for them, but if the GH and KH are similar, it holds the TDS at a higher level. I did not have a TDS meter when I did the longevity work initially, so I cannot offer break point or guidelines on those coupled with GH an KH. My tap GH is slightly lower than the KH, and I do not do any special adjustment for either... If i had to adjust, i would likely do both to about the same level..

[RTR]

Additional comment: Some folks on here know that I believe KH to be more important to F-8s than salinity, but both are highly significant at least I just do not have enough data to give statistically significant results. That was a late realization in looking at full lifespans in varied water conditions, and I did not get enough total lifetimes in for significance. But there was enough data to convince me.

This was all because my water was moderately hard (GH) and alkaline (KH) and similar KH but a degree or a bit more higher in KH than GH (7+ degree GH versus 8 plus to 9 degrees KH). This made me realize that relatively high KH alone could be a non-trivial contributor to longevity for these fish. All the test tanks had OE_RFUG filters with 1/2" or or very slightly more aragonite, so it kept the KH high at all times I had been testing for KH routinely, as I considered it significant for stability - without such, inert substrates showed significantly more pH fluctuation, which can affect biofiltration also. So in preliminary trials I selected the setups to be all the same and built a rack for them.

I could not read any difference in specific gravity 1.0025 and 1.003, nor any serious significant difference between those and 1.005. But the 1005 numbers were not quite as good as the lower numbers. On reevaluation of the data, I suspected that if folks did not use high KH water at least equal to mine or higher, then 1.005 would likely give better results for them, as it would boost the KH above that of 1.003. That was where the idea hit that I had not tested enough - If I had run RO water, my low specific gravity would likely not been as good as it was. The TDS of the two solutions, starting with RO or with moderately alkaline tap, are significantly different. That has to matter to the fish. But by then the test rack was long disassembled and disposed of, and no way would I start another 20-year study. That is one fish room about 80% dedicated to the study. Not for me, one in a lifetime is enough, thank you very much anyway.

HTH

[JRC3]

Well instead of the RFUG I decided to use the mixing pump and run it through a small bucket of the crushed coral and aragonite. The PVC is teed and capped off with holes drilled in it for a more even flow.

http://i280.photobucket.com/albums/kk16 ... CI0726.jpg

I put in an old filter tube which helps with the mixing and filling the tank with aged water. It hangs on and couldn't be easier.
http://i280.photobucket.com/albums/kk16 ... CI0727.jpg
http://i280.photobucket.com/albums/kk16 ... CI0728.jpg

So far I haven't gotten any big numbers but the vessel and tank have only been up for a little over a week. The tank KH is at 5 degrees, the mixing vessel is at 6 and my tap water is at 4. I'm hoping as the tank ages I'll see some bigger numbers.

In the tank itself I have 15 pounds of aragonite sand and about 10 pounds of crushed coral mixed in with some PFS. I also have a media bag in one filter filled with crushed aragonite. The bucket in the mixing vessel has about 20 pounds of crushed aragonite in it.

We'll see how it does and I'll post results.

[Flutter]

Wow, good luck with that. Our water comes out of the tap at about 18dH. Haven't tested it in the F8 tank though.

[RTR]

Everything helping the KH is a plus for F-8s IMHO & IME. But it is not fast. It will edge up slowly. Pre-treating the water as you are doing is a big help for me as well, but it is not instant. Aragonite is slow, but faster and more effective than crushed coral. You eventually stabilize at the highest possible KH for your water supply which is good for the fish.

Having it in the tank as well is a plus in that it can respond to nitrification acidity immediately - which gives you better stability long-term. Otherwise (as with most tanks) the KH & pH will drift down a bit between partials. That is unavoidable without aragonite - nitrification is an acid-producing process, it uses up KH while it is doing its job.

[JRC3]

As I was adding another piece of cuttlebone to my snail tank I wondered if it would help increase the KH in my brackish tank. Does anyone know if it would and if there are any drawbacks?

[RTR]

The cuttlebone is easily accessible top raspers, but not terribly soluble. Rather expensive as a water supplement as well.