I could use some advice on Gh and Kh levels please

[Nick1234]

Our well water is high PH and very hard water and so we switched to bottled RO water for out tanks...everyting has been fine until recently while browsing the forum I read about this water not having enough minerals for plants and fish. So I got a test kit from API and found that we have very little KH in both our well water and of course the bottled water. Last water change I mixed in some well water with the RO water and now have 1 test drop for KH and 7 test drops for GH with a PH of around 7.8. Should I be concerned about the low KH ? The PH generally stays fairly stable and all the fish and plants are doing well. Am I worrying about nothing or is this a long term problem? Thanks for any help....Nick

 

[Aiken Drum]

KH is important for a couple of reasons.

• KH absorbs acid, stabilising pH. A lot of the natural processes that happen in aquariums acidify the water. Fish and plant respiration expire CO2 into the water, this disolves forming carbonic acid. The nitrogen cycle turns ammonia into nitrate. Nitrate disolves in the water forming nitric acid. KH absorbs these acids and prevents them from lowering pH, this is called buffering. Once the buffering is gone there is nothing to prevent pH from rapidly dropping, and pH swings arent healthy for fish.
• The nitrogen cycle needs a carbon source to turn ammonia into nitrite and nitrate, this comes from your KH. With no KH the nitrogen cycle cant function and ammonia builds up, potentially to toxic levels. This isnt normally an issue because ammonia isnt toxic in acidic conditions, but if your water has low KH, and high pH the ammonia build up can be harmful.

In addition, minerals are needed for general health for some fish. Some fish suit soft acidic water, like tetras. Some fish prefer harder, higher pH water, like livebearers.

If you are using RO water you can add these minerals through mixing salts to tailer the water to the specific preferences of the fish you wish to keep. There are salts that raise the general hardness (GH) without effecting KH, and different salts that raise KH without effecting GH. You can mix different amounts of each type of salt to get GH and KH right where you want them. Mixing tap water with your RO can similarly get you somewhere between the 2. A 50% mix of RO and tap should halve the GH and KH of the tap water.

Your RO may or may not be an issue, depends on the specific fish species. The acidification may be something that happens over time. As long as your KH isnt zero you will get some buffering before the KH runs out, if you do enough water changes to replenish the KH it may never be an issue, but its something I would monitor. You havent mentioned what your KH actually is. 3 or 4 degrees (60 to 80ppm) is a good level of KH as long as you do your water changes and prevent it running out.

 

[Nick1234]

Thanks Aiken for the education.
Using an API test kit
Well water reads 196.9 GH
17.9 KH
8.0 PH
Tank water is a mixture of approx. 1/3 well water and 2/3 RO
Reads 107.4 GH
17.9 KH
7.6-- 7.8 PH


Unfortunately for me my well water has high GH ( 196.9 ppm ) with very low KH and around an 8.0 PH. I can regulate the GH and PH of the RO water using well water but if I add some sort of KH plus product will it make my PH even higher which is already 7.6 to 7.8. Looks like I may need to go straight RO water and find the proper additives to balance the Gh and KH. Does that make any sense to you? my head hurts--who knew fish keepers needed a chemistry degree

 

[Aiken Drum]

Adding a KH buffer will increase the pH, but if it's already high then it probably won't raise by any noticable degree. The only way to know is to give it a go. Do some trials in a bucket and see what happens.

You haven't mentioned other parameters like ammonia, nitrite or nitrate. If you are seeing zero ammonia and nitrite, and nitrate is rising between water changes your cycle is functioning OK, and you must have enough KH for that. You say the pH is stable, so you must be maintaining enough buffering.

But your betta wasn't doing well in the neat RO, and things improved when you added some mineral content.

Im not sure if we are talking about 1 or more aquariums, and apart from the betta what fish you are keeping. The simplest solution is keep fish that suit the water, rather than trying to adjust water to suit the fish.

 

[Nick1234]

LOL ! Sorry to drag this out Aiken. I appreciate your patience. We started with one 10 gallon tank and then fell down the rabbit hole of fish keeping. We now have the original 10 gal plus a 29 gal. tank and 3 bettas in 3 separate 3 gal tanks. I know 3 gal is not big enough but it's what my wife likes. We started out just using our well water but could never get the tank water crystal clear so switched to RO water not realizing the problem with mineral depletion. We have 2 angel fish male and female , 3 tetras , 3 cory catfish , 3 neon tetras and some random snails in the large tank. The angels are about 2 to 3 inches across right now but growing fast. We have 6 tetras in the 10 gallon tank. Unfortunately we jumped into buying fish with little research into how to care for them. I'm sure you've seen it many times before. We do water changes on all the tanks once a week and have 0 ammonia and nitrites with nitrates climbing during the week between water changes. I thought I had this stuff figured out until I learned about my mineral problems But that leads us to all this drama over fish. Thanks for your advice..Nick

 

[Andy Sager]

LOL ! Sorry to drag this out Aiken. I appreciate your patience. We started with one 10 gallon tank and then fell down the rabbit hole of fish keeping. We now have the original 10 gal plus a 29 gal. tank and 3 bettas in 3 separate 3 gal tanks. I know 3 gal is not big enough but it's what my wife likes. We started out just using our well water but could never get the tank water crystal clear so switched to RO water not realizing the problem with mineral depletion. We have 2 angel fish male and female , 3 tetras , 3 cory catfish , 3 neon tetras and some random snails in the large tank. The angels are about 2 to 3 inches across right now but growing fast. We have 6 tetras in the 10 gallon tank. Unfortunately we jumped into buying fish with little research into how to care for them. I'm sure you've seen it many times before. We do water changes on all the tanks once a week and have 0 ammonia and nitrites with nitrates climbing during the week between water changes. I thought I had this stuff figured out until I learned about my mineral problems But that leads us to all this drama over fish. Thanks for your advice..Nick

For what it's worth, 3 gallons for a Betta is fine as long as the water quality stays good. Most of the Asian Betta breeders keep them in 1 gallon tanks.
Regarding your RO water issues, as Aiken explained, fish need more than the H2 and the O. Fish "absorb" water through osmoregulation so that if there are no minerals in the water, it sucks them out of the fish. :^0 This is why the video would have showed us whether it's more a swim bladder issue or something else. Despite what their wild counterparts live in, the domesticated Bettas we have available can live in rock hard water like yours. I used to breed hundreds of them in South Florida water which is similar to your well water.

As for the fish in with the Angelfish pair, at some point, those Neons are going to be a meal for them. What kind are the other Tetras you have in with them and in the other 10 gallon tank? ( They may be better together in the one tank. )

 

[Nick1234]

Thanks Andy, when we got our tanks the lady at Pet Smart sold us a bunch of fish and assured us that they would all do fine together so we ended up with 2 overstocked tanks.
In the big tank with the angels we have 3 black skirted tetras along with the neons and cats. In the 10 gal tank we have 3 serpae tetras and 3 pink glofish. We may move the other 3 tetras into the 10 gal tank but don't want to overcrowd them. All the tetras were in the big tank but the angels laid some eggs a couple of weeks ago and got real grumpy with the other fish so we started rearranging things. Not really sure how many can fit in that 10 gallon tank. Thanks for replying....Nick

 

[Andy Sager]

Thanks Andy, when we got our tanks the lady at Pet Smart sold us a bunch of fish and assured us that they would all do fine together so we ended up with 2 overstocked tanks.
In the big tank with the angels we have 3 black skirted tetras along with the neons and cats. In the 10 gal tank we have 3 serpae tetras and 3 pink glofish. We may move the other 3 tetras into the 10 gal tank but don't want to overcrowd them. All the tetras were in the big tank but the angels laid some eggs a couple of weeks ago and got real grumpy with the other fish so we started rearranging things. Not really sure how many can fit in that 10 gallon tank. Thanks for replying....Nick

Yeah, when Cichlids spawn ( Angelfish are part of the Cichlid family), they get very territorial. Breeding pairs are not the best to have in community tanks because of that. A 29 gal is not that large of a tank so they can get really obnoxious when they spawn. Unless you plan on trying to raise the fry, the good news is that fish eggs are a very nutritious meal so not much needs to be done. If you want to try and raise the fry, the other fish really should be removed. As for the Black Skirts, the Glo-Tetras are actually made from the Black Skirts so mixing them together is fine.
You do need to be aware of this possibility: It's not unusual for Angels to lose a few spawns, especially when they first start spawning however, if they lose too many, I've seen pairs where one turns on the other as if they are blaming the other for losing the spawn. If you see this kind of behavior, you really should split up the pair. If you don't have another tank, use a tank divider. Sometimes just separating them for a few months is all it takes but that is not always fool proof. I've bred hundreds of pairs of Angels and can tell you, they all have their idiosyncrasies that don't always make sense. Case in point, I had one female that bred with 3 different males. The problem was she had to beat the crap out of them first and she took out 1 eye on each male. After that, she would spawn with them on a regular basis. I had another pair where the male would follow the female in the typical spawning action but instead of fertilizing the eggs, he would eat them as fast as she was laying them. With this male, you could actually see the lightbulb go off in his head that that was not the right thing to do and then he started to fertilize instead of eat the eggs. ( At least I was able to get 1/4 of the spawn after he ate the other 3/4. ) Like I said, Angelfish can be nuts. LOL
You also have another option: If you can get at least one of those eggs to hatch, that will prove that both fish are fertile. If they are fertile, you could sell or trade the pair in for other fish, money or store credit for usually more money than for 2 fish that are not a mated pair. Just something to think about. Usually people trade in old pairs but a young fertile pair could be worth some bucks.
As for the lady at Petsmart, I'd find another store or a different sales clerk. Just sayin'

 

[Nick1234]

Well we never really thought about raising fish and would probably just let nature take it's own course as far as the eggs go. The female has laid eggs twice and after several days they ate them. We are going to move out the other fish and let the angels have this tank as their own love nest I think. Thanks for the fish stories...very interesting. Nick

 

[Andy Sager]

Well we never really thought about raising fish and would probably just let nature take it's own course as far as the eggs go. The female has laid eggs twice and after several days they ate them. We are going to move out the other fish and let the angels have this tank as their own love nest I think. Thanks for the fish stories...very interesting. Nick

That's usually best.
Typically, especially with young fish, the first few spawns are duds while they figure out the process. Feel free to check out my pics ( Media added by Andy Sager ) of Angelfish in my last hatchery so you know what to look for. If you want to get into breeding the Angels, this is an old thread here ( Wigglers At Last!!!!! ) which was an ongoing conversation between professional Angelfish breeders, casual breeders and hobbyists here. Just about everything Angelfish was discussed in that thread so lots of information.