What would be an acceptable level for KH in my F8 tank? I changed my substrate over from ornamental gravel to aragonite sand last week,
the pH has improved to 7.8 (currently - most likely increasing) but the KH is at 70ppm?
Will a layer of inch-thick aragonite take a while to alter the KH of a 175 litre tank?
As I recall it's something like a range from 5 to 15 for KH.
RTR wrote:Yup, you have the right stuff now. It will not give completely stable conditions, but that is not essential - it will give far better stability than any other substrate. The aragonite - being the most soluble form available - will star dissolving faster as the KH is depleted, bringing more into solution faster just as needed.
While ideally we could want highly stable water parameters, that is not realistic in our semi-closed system regular tank set-ups and care. So we settle for some fluctuation, using material for the substrate which is highly responsive to water conditions. That gives a better margin of safety than we would have otherwise with different substrates.
Back when I ran the F-8 longevity study, I added a late study group with the good substrate (aragonite) versus inert substrate (very small gravel - which does not contribute tho either GH or KH). I did run enough numbers of test tanks to show significance in laboratory-style trials, but the fish over the aragonite did live longer and healthier lives than those over the inert gravel. It appeared that the most responsive substrate was likely as important as was the specific gravity. Even without being able to show strong statistical significance (due to too few fish in these late groups), it was enough to convince me. All of my longest lived fish in the main study were also over such substrates, which reinforced the findings.
If anything, aragonite may be more important to low density BW than it is to mid-level BW or higher density BW and SW. With more marine mix in the water in those, we have more buffering present anyway from the increased levels of the marine mix itself.
I have to try to get some sort of article into the library on this factor - to keep the importance of this available to everybody.
Good to hear. As I've said before my water's KH is only 5 and I want it harder for my F8 and BBGs.
I have one of the Rubbermade "Brute" 32g trashcans to mix my water in and I've also decided to let it run/mix the full week between water changes. And just last night I added 15 pounds of puka shell aragonite to the can hoping that it will increaes my hardness. Later, hopefully shortly, I will be switching everyone over to a larger tank and at that time I will add a finer aragonite as substrate and I think I will also just leave the aragonite in my mixing container too.
There are many knowledgeable fish keepers on this forum willing to help and give great advice...The advice is free; What you choose to do with it gives it value.
You probably saw the quote was from your other thread.
My test kit measure in degrees and not ppm. I don't know the conversion of the two.
There are many knowledgeable fish keepers on this forum willing to help and give great advice...The advice is free; What you choose to do with it gives it value.
Pretty much already said/cited, but my BW mixing is close to what you are adopting. I age the water, premixed to the desired specific gravity in a heated circulated vessel. I use spare canisters to circulate the water for BW, with araginite rubble in the canister in mesh bags. I swap out the bags for dried rinsed ones about monthly - biofilm can sometimes help, sometimes hinder the solution of the aragonite, so in these vessels I avoid some of that by trading out the aragonite to kill the biofilms periodically by drying and rinsing. But I admit that I have not done comparison trials of that versus a simple layer in the vessel to see which is really better. If I had a layer in the bottom of the vessel, i would likely run RFUG to get the fines from the mix into solution better.
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.
RFUG, great idea... I happen to have one laying around as well as a 12"x12" UGF plate that should fit inside the can.
So now I'm gonna have 3 cords going into on trash can full of water...What will people think?
There are many knowledgeable fish keepers on this forum willing to help and give great advice...The advice is free; What you choose to do with it gives it value.
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.
My Puffers: Puffers I have kept: T lineatus T miurus A modestus T biocellatus C valentini C coranata C papuan C lorteti DPs suvattii burrfish T niphobles
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..
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.
