Question about GH and KH

[gcuss]

Ok, first off, I'm brand new, so forgive me if this is a basic question...

I recently finished moving a few of my Koi in for the winter so they can grow a bit, and I can prove to my friends that I've completely lost my mind and think it's acceptable to have Koi in the laundry room. (I can't afford to heat the outside pond, so a few lucky ones get to come in for the winter.. gets cold up here in WA)

I think my "set up" is going to be OK as far as controlling the ammonia and nitrites and such. Time will tell, I'm just going to monitor it closely. (I may start a different thread regarding my winter set up)

Anyway, I'm just curious about my water hardness. Outside my Gh is usually around 60 and my Kh is around 80. However, inside my Gh is 120 as is my Kh. Is this a problem? My water is municipal and comes out at 120/120... (Due to some newbie mistakes I've done some MAJOR water changes outside but even after changing water daily to fix a mistake the hardness is pretty stable at 60/80)
My nitrite is 0, ammonia is 0, and Ph is 7.6.

Temp in outside pond is 64, and inside is 75. I don't know if temp. makes a difference, but thought I would mention just in case.

I understand that water hardness can do different things to the colors of the fish so I'd like to have it optimum for them.

Oh, and thanks to Dick B for the great seminar/"koi college" at the recent show in Bothell. I picked up a few Tosia while there and have now moved from complete pond mutts from the local nursery, to ... partial pond mutts? (I think they're beautiful fish and am excited to see how they develop)

Thanks for any feedback.

Grant

[MikeM]

Your hardness and KH are fine. While your pond water is very much on the soft side, the indoor water is quite moderate. I'm assuming you use a different water source outdoors? If not, there has to be a reason behind the difference.

[gcuss]

Actually, the source for the pond and inside are the same... Straight from the tap/hose bib.

Why would my water soften outside? A couple of months ago, I used Malifix, which I think softens the water some (guessing here), however, since then my weekly water changes should have flushed the Malifix out of the system.

Thanks for the help. I can assume 120/120 is good for the fish then?

Grant

[bekko]

Your pond must have a lot of accumulated debris.

The process of turning fresh fish waste into the more stable humic organic matter produces acids. These acids react with the carbonates and bicarbonates (the primary components of KH) to reduce or deplete alkalinity.

The humic organic matter on the pond bottom then binds with calcium and magnesium ions (the primary components of GH) pulling them out of solution. This is the same process as using peat to soften water.

Lower GH and KH generally allows beni to develop better. However, some would argue that allowing humic organic matter (mulm) to accumulate in the pond is a dangerous way to soften water because the excess organic matter is often associated with disease outbreaks.

Your outside pond probably has a lower pH than the inside tank.

-steve

[MCA]

koi in laundry room?

How many koi at what length...in how many gallons? You must have a huge laundry room to have room for several hundred gallons for a koi tank.

[gcuss]

It's a laundry/mud room. Stacked the dryer on top of the washer, this made the room I needed.

Set up is sorta like this:

Two 150 gallon agriculture tubs joined by 1 1/2 pipe via the bulkhead fittings at the bottom.

In tub #1: 500 GPH submersible pump, 2- 12" airstones, 300 Watt aquarium heater.

The pump feeds into a tetra pond pressurized filter I brought in from the outside pond so it's already mature (I kept the water that was in the filter and had the pump flowing de-chlorinated water through it inside of 45 min. so I wouldn't hurt the bacteria too badly). I put a valve inline so I could throttle back the flow a bit and I've got it pretty good now so that there aren't any dead spots for waste accumulation but not so much current that the fish can't rest. I'm monitoring my levels 2 times a day for the first while to make sure I'm not having any trouble and am prepared to put bio media into tub #1 if I have any nitrite/ammonia readings. So far it's been 6 days with regular feeding and haven't had so much as a whiff of ammonia/nitrite.

In tub #2: 4 - 4"-6" tosai

Just the hardness made me wonder...

Bekko:

Actually, no. My pond outside is covered and my bottom drain works great for keeping the floor clean. Skimmer is running for the errant pine needle that swoops in from the wind. Very min. debris in my outside pond, and the PH is higher outside. 7.9 last reading. Interesting explanation of the effects on water hardness. Man you guys are knowledgeable. Thanks!!

Would the hardness and the slight Ph change cause a couple of fish to flash a bit? I can't imagine I've got a parasite seeing as there were no problems with flashing and such outside and the inside water came straight from the tap... No new fish added

Anyway, thanks for the responses. the help is appreciated!

Grant

[MikeM]

The change in water conditions often results in a little flashing. When that is the cause, the flashing generally stops after 48 hours. Flashing also can occur when ammonia starts to build up. Keep watching closely.

How large were the water changes outdoors, how many and how frequent?

[gcuss]

Mike:

The water changes were 30 - 50 % following a brutal lesson in water flows and plumbing do's and don'ts. Did that for about 5 days straight a couple months ago to deal with a nitrite crisis. Special note, simply slapping on a couple of tee's and adding a second pressure filter to have two in parallel doesn't actually work and can make a whole filter full of anaerobic bacteria, which consiquently can drive your nitrite into orbit. Compound that with me wasting 3 cruicial days trying to figure out what the heck is going on and you end up with a sick fish or two. Finally figured out, and consiquently fixed the offending problem. The worst of it was, that it was shortly after a power outage where my water went nasty and the fish only enjoyed about 3 days of decent water before I got creative and attempted to "kill them with kindness" by adding another filter.

But normally, 10% per week as maintenance.

[MikeM]

My guess is along the same lines as Bekko's. That is, the nitrifier community in the pond is very busy, which consumes alkalinity and results in acid production reducing overall hardness. There could also be a plant debris issue. Pine needles are very acidic. During the periods of the year when the needles are falling more heavily, there could be water challenges, especially if skimmer baskets are emptied only once per week.

Until you find the cause for the differential, I would suggest increasing weekly water changes. You should know, however, that I am very biased in favor of water changes. I have very good filtration on my pond and what most folks would consider low or moderate stocking (14 larger koi and 5 in their 2d year in 12,500 gallons). I change 35% or more weekly. If I'm really pushed for time, it may only be 30%.

Some folks will question worrying over it since the outdoor pH and softness are fine in themselves. My thinking is that something is occurring to dramatically alter your water parameters in the pond compared to indoors. Until the cause is known, I assume there is a risk factor involved. Whenever the pond water is very different in pH or hardness/alkalinity compared to the source water (after allowed to sit 24 hours to let compressed gasses etc to escape), there is a potential problem lurking. When you find the cause, it may be no big deal. Or, it may be something fundamental. Perhaps no ill consequence ever occurs. But, there could be a pH crash, bio-filter die-off or the like just days away... and avoided only because you never miss that weekly water change (except the week before all the fish got sick?).

Anyway, that's my speculation for what it's worth.

[KoiCop]

What Mike said.

I would increase your frequency of water changes with the goal of changing out double or triple your current weekly volume -- but in smaller individual changes.

Bringing the readings back to baseline parameters this way is far less stressful on your fish than letting the parameters get further out of whack then snapping them back in one fell swoop.

Increasing the total volume of water changes will not only increase the levels of good stuff coming in (like carbonates, trace minerals, etc.), it will increase the levels of bad stuff going out (like nitrates, DOCs, etc.).

Good luck,